Nondeterminism in integration test double-read-modf on Windows

Regression test `double-read-modf` on Windows sometimes fails on:
```
Test (double-read-modf.c -a pic32 -f elf -c gcc -C -O0 -g)

AssertionError: compilation of file 'regression-tests\integration\current\double-read-modf\outputs\Test (double-read-modf.c -a pic32 -f elf -c gcc -C -O0 -g)\double-read-modf.out.c' failed with return code 1; output:
regression-tests\integration\current\double-read-modf\outputs\Test (double-read-modf.c -a pic32 -f elf -c gcc -C -O0 -g)\double-read-modf.out.c: In function 'func':
regression-tests\integration\current\double-read-modf\outputs\Test (double-read-modf.c -a pic32 -f elf -c gcc -C -O0 -g)\double-read-modf.out.c:27:5: warning: implicit declaration of function 'fpmodf' [-Wimplicit-function-declaration]
fpmodf((int32_t)x, (int32_t)&intPart);
^~~~~~
double-read-modf.out.c:(.text+0x2d): undefined reference to `fpmodf'
```

Looks like `fpmodf()` is sometimes generated instead of `modff()`.