unixport on Apple M-chips doesn't compile

Compiles fine with micropython master

```
CC ../../../usermods/secp256k1/mpy/libsecp256k1.c
../../../usermods/secp256k1/mpy/libsecp256k1.c:496:48: warning: passing 'char *' to parameter of type 'unsigned char *' converts between pointers to integer types where one is of the unique plain 'char' type and the other is not [-Wpointer-sign]
int res = secp256k1_ec_privkey_negate(ctx, vstr.buf);
^~~~~~~~
../../../usermods/secp256k1/secp256k1/include/secp256k1.h:641:20: note: passing argument to parameter 'seckey' here
unsigned char *seckey
^
../../../usermods/secp256k1/mpy/libsecp256k1.c:578:51: warning: passing 'char *' to parameter of type 'unsigned char *' converts between pointers to integer types where one is of the unique plain 'char' type and the other is not [-Wpointer-sign]
int res = secp256k1_ec_privkey_tweak_add(ctx, priv2.buf, tweakbuf.buf);
^~~~~~~~~
../../../usermods/secp256k1/secp256k1/include/secp256k1.h:680:20: note: passing argument to parameter 'seckey' here
unsigned char *seckey,
^
../../../usermods/secp256k1/mpy/libsecp256k1.c:1230:25: warning: assigning to 'unsigned char *' from 'char *' converts between pointers to integer types where one is of the unique plain 'char' type and the other is not [-Wpointer-sign]
bfactors[i] = vstr.buf;
^ ~~~~~~~~
../../../usermods/secp256k1/mpy/libsecp256k1.c:1472:56: warning: passing 'char *' to parameter of type 'unsigned char *' converts between pointers to integer types where one is of the unique plain 'char' type and the other is not [-Wpointer-sign]
int res = secp256k1_surjectionproof_serialize(ctx, vstr.buf, &l, ptr);
^~~~~~~~
../../../usermods/secp256k1/secp256k1/include/secp256k1_surjectionproof.h:93:18: note: passing argument to parameter 'output' here
unsigned char *output,
^
../../../usermods/secp256k1/mpy/libsecp256k1.c:1559:46: warning: passing 'char *' to parameter of type 'unsigned char *' converts between pointers to integer types where one is of the unique plain 'char' type and the other is not [-Wpointer-sign]
int res = secp256k1_rangeproof_sign(ctx, vstr.buf, &prooflen,
^~~~~~~~
../../../usermods/secp256k1/secp256k1/include/secp256k1_rangeproof.h:252:18: note: passing argument to parameter 'proof' here
unsigned char *proof,
^
../../../usermods/secp256k1/mpy/libsecp256k1.c:1724:48: warning: passing 'char *' to parameter of type 'unsigned char *' converts between pointers to integer types where one is of the unique plain 'char' type and the other is not [-Wpointer-sign]
int res = secp256k1_rangeproof_rewind(ctx, vbf_out.buf, &value_out,
^~~~~~~~~~~
../../../usermods/secp256k1/secp256k1/include/secp256k1_rangeproof.h:208:18: note: passing argument to parameter 'blind_out' here
unsigned char *blind_out,
^
../../../usermods/secp256k1/mpy/libsecp256k1.c:1725:29: warning: passing 'char *' to parameter of type 'unsigned char *' converts between pointers to integer types where one is of the unique plain 'char' type and the other is not [-Wpointer-sign]
msg.buf, &msglenout,
^~~~~~~
../../../usermods/secp256k1/secp256k1/include/secp256k1_rangeproof.h:210:18: note: passing argument to parameter 'message_out' here
unsigned char *message_out,
^
../../../usermods/secp256k1/mpy/libsecp256k1.c:1888:61: warning: passing 'char *' to parameter of type 'unsigned char *' converts between pointers to integer types where one is of the unique plain 'char' type and the other is not [-Wpointer-sign]
int res = secp256k1_rangeproof_rewind_preallocated(ctx, vbf_out.buf, &value_out,
^~~~~~~~~~~
../../../usermods/secp256k1/mpy/config/rangeproof_preallocated/rangeproof_preallocated.h:10:17: note: passing argument to parameter 'blind_out' here
unsigned char *blind_out, uint64_t *value_out, unsigned char *message_out, size_t *outlen, const unsigned char *nonce,
^
../../../usermods/secp256k1/mpy/libsecp256k1.c:1889:29: warning: passing 'char *' to parameter of type 'unsigned char *' converts between pointers to integer types where one is of the unique plain 'char' type and the other is not [-Wpointer-sign]
msg.buf, &msglenout,
^~~~~~~
../../../usermods/secp256k1/mpy/config/rangeproof_preallocated/rangeproof_preallocated.h:10:64: note: passing argument to parameter 'message_out' here
unsigned char *blind_out, uint64_t *value_out, unsigned char *message_out, size_t *outlen, const unsigned char *nonce,
^
9 warnings generated.
CC ../../../usermods/udisplay_f469/display_unix.c
CC ../../../usermods/udisplay_f469/display_unix_sdl.c
In file included from ../../../usermods/udisplay_f469/display_unix_sdl.c:1:
In file included from ../../../usermods/udisplay_f469/lv_sdl_hal/SDL/modSDL.c:3:
In file included from ../../../usermods/udisplay_f469/lv_sdl_hal/SDL/SDL_mouse.h:25:
In file included from /usr/local/include/SDL2/SDL.h:38:
In file included from /usr/local/include/SDL2/SDL_cpuinfo.h:99:
In file included from /Library/Developer/CommandLineTools/usr/lib/clang/13.1.6/include/immintrin.h:13:
In file included from /Library/Developer/CommandLineTools/usr/lib/clang/13.1.6/include/x86gprintrin.h:15:
/Library/Developer/CommandLineTools/usr/lib/clang/13.1.6/include/hresetintrin.h:42:27: error: invalid input constraint 'a' in asm
__asm__ ("hreset $0" :: "a"(__eax));
^
In file included from ../../../usermods/udisplay_f469/display_unix_sdl.c:1:
In file included from ../../../usermods/udisplay_f469/lv_sdl_hal/SDL/modSDL.c:3:
In file included from ../../../usermods/udisplay_f469/lv_sdl_hal/SDL/SDL_mouse.h:25:
In file included from /usr/local/include/SDL2/SDL.h:38:
In file included from /usr/local/include/SDL2/SDL_cpuinfo.h:99:
In file included from /Library/Developer/CommandLineTools/usr/lib/clang/13.1.6/include/immintrin.h:17:
/Library/Developer/CommandLineTools/usr/lib/clang/13.1.6/include/mmintrin.h:50:12: error: invalid conversion between vector type '__m64' (vector of 1 'long long' value) and integer type 'int' of different size
return (__m64)__builtin_ia32_vec_init_v2si(__i, 0);
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
/Library/Developer/CommandLineTools/usr/lib/clang/13.1.6/include/mmintrin.h:129:12: error: invalid conversion between vector type '__m64' (vector of 1 'long long' value) and integer type 'int' of different size
return (__m64)__builtin_ia32_packsswb((__v4hi)__m1, (__v4hi)__m2);
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
/Library/Developer/CommandLineTools/usr/lib/clang/13.1.6/include/mmintrin.h:159:12: error: invalid conversion between vector type '__m64' (vector of 1 'long long' value) and integer type 'int' of different size
return (__m64)__builtin_ia32_packssdw((__v2si)__m1, (__v2si)__m2);
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
/Library/Developer/CommandLineTools/usr/lib/clang/13.1.6/include/mmintrin.h:189:12: error: invalid conversion between vector type '__m64' (vector of 1 'long long' value) and integer type 'int' of different size
return (__m64)__builtin_ia32_packuswb((__v4hi)__m1, (__v4hi)__m2);
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
/Library/Developer/CommandLineTools/usr/lib/clang/13.1.6/include/mmintrin.h:216:12: error: invalid conversion between vector type '__m64' (vector of 1 'long long' value) and integer type 'int' of different size
return (__m64)__builtin_ia32_punpckhbw((__v8qi)__m1, (__v8qi)__m2);
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
/Library/Developer/CommandLineTools/usr/lib/clang/13.1.6/include/mmintrin.h:239:12: error: invalid conversion between vector type '__m64' (vector of 1 'long long' value) and integer type 'int' of different size
return (__m64)__builtin_ia32_punpckhwd((__v4hi)__m1, (__v4hi)__m2);
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
/Library/Developer/CommandLineTools/usr/lib/clang/13.1.6/include/mmintrin.h:260:12: error: invalid conversion between vector type '__m64' (vector of 1 'long long' value) and integer type 'int' of different size
return (__m64)__builtin_ia32_punpckhdq((__v2si)__m1, (__v2si)__m2);
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
/Library/Developer/CommandLineTools/usr/lib/clang/13.1.6/include/mmintrin.h:287:12: error: invalid conversion between vector type '__m64' (vector of 1 'long long' value) and integer type 'int' of different size
return (__m64)__builtin_ia32_punpcklbw((__v8qi)__m1, (__v8qi)__m2);
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
/Library/Developer/CommandLineTools/usr/lib/clang/13.1.6/include/mmintrin.h:310:12: error: invalid conversion between vector type '__m64' (vector of 1 'long long' value) and integer type 'int' of different size
return (__m64)__builtin_ia32_punpcklwd((__v4hi)__m1, (__v4hi)__m2);
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
/Library/Developer/CommandLineTools/usr/lib/clang/13.1.6/include/mmintrin.h:331:12: error: invalid conversion between vector type '__m64' (vector of 1 'long long' value) and integer type 'int' of different size
return (__m64)__builtin_ia32_punpckldq((__v2si)__m1, (__v2si)__m2);
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
/Library/Developer/CommandLineTools/usr/lib/clang/13.1.6/include/mmintrin.h:352:12: error: invalid conversion between vector type '__m64' (vector of 1 'long long' value) and integer type 'int' of different size
return (__m64)__builtin_ia32_paddb((__v8qi)__m1, (__v8qi)__m2);
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
/Library/Developer/CommandLineTools/usr/lib/clang/13.1.6/include/mmintrin.h:373:12: error: invalid conversion between vector type '__m64' (vector of 1 'long long' value) and integer type 'int' of different size
return (__m64)__builtin_ia32_paddw((__v4hi)__m1, (__v4hi)__m2);
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
/Library/Developer/CommandLineTools/usr/lib/clang/13.1.6/include/mmintrin.h:394:12: error: invalid conversion between vector type '__m64' (vector of 1 'long long' value) and integer type 'int' of different size
return (__m64)__builtin_ia32_paddd((__v2si)__m1, (__v2si)__m2);
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
/Library/Developer/CommandLineTools/usr/lib/clang/13.1.6/include/mmintrin.h:416:12: error: invalid conversion between vector type '__m64' (vector of 1 'long long' value) and integer type 'int' of different size
return (__m64)__builtin_ia32_paddsb((__v8qi)__m1, (__v8qi)__m2);
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
/Library/Developer/CommandLineTools/usr/lib/clang/13.1.6/include/mmintrin.h:439:12: error: invalid conversion between vector type '__m64' (vector of 1 'long long' value) and integer type 'int' of different size
return (__m64)__builtin_ia32_paddsw((__v4hi)__m1, (__v4hi)__m2);
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
/Library/Developer/CommandLineTools/usr/lib/clang/13.1.6/include/mmintrin.h:461:12: error: invalid conversion between vector type '__m64' (vector of 1 'long long' value) and integer type 'int' of different size
return (__m64)__builtin_ia32_paddusb((__v8qi)__m1, (__v8qi)__m2);
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
/Library/Developer/CommandLineTools/usr/lib/clang/13.1.6/include/mmintrin.h:483:12: error: invalid conversion between vector type '__m64' (vector of 1 'long long' value) and integer type 'int' of different size
return (__m64)__builtin_ia32_paddusw((__v4hi)__m1, (__v4hi)__m2);
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
/Library/Developer/CommandLineTools/usr/lib/clang/13.1.6/include/mmintrin.h:504:12: error: invalid conversion between vector type '__m64' (vector of 1 'long long' value) and integer type 'int' of different size
return (__m64)__builtin_ia32_psubb((__v8qi)__m1, (__v8qi)__m2);
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
fatal error: too many errors emitted, stopping now [-ferror-limit=]
20 errors generated.
make[1]: *** [build/udisplay_f469/display_unix_sdl.o] Error 1
make: *** [unix] Error 2
```

Start with the unixport build that compiles usermods/udisplay_f469/display_unix_sdl.c, then inspect the included SDL2 headers and the Apple Clang errors in immintrin.h and mmintrin.h. Reproduce the build on an Apple M-chip and determine the platform-specific compilation change needed; done means the unixport target compiles successfully.

Written by the indexing model from the issue text.