Build failure on Mac OS X 10.13.2 (Unable to specify soname (is Darwin supported?))

Hi,

Running `./configure` works with no errors at first, but running `make` afterwards yields:
```sh
Makefile:4: .build/config.mk: No such file or directory
Makefile:35: .build/cppcache: No such file or directory
make: *** No rule to make target `.build/cppcache'. Stop.
```
(and indeed `.build` only contains `check.c`)

So I went searching in the `configure` script for what's going wrong --
```sh
201 for flag in -fPIC -Wl,--no-undefined -Wl,--as-needed
202 do
203 test_ldflags "$flag"
204 done
```
We never make it past line 204: `test_ldflags` goes through with argument `-fPIC`, but the next argument, `-Wl,--no-undefined` fails and the script exits (I'm not entirely sure if the arguments are being passed correctly to the function, but this is what's being passed).

So I removed the line that causes the script to exit on failure, 178:
```diff
170 test_ldflags() {
171 [ ! -e "$outdir"/check.c ] && cat <<-EOF > "$outdir"/check.c
172 int main(void) { return 0; }
173 EOF
174 if $CC "$@" -o /dev/null "$outdir"/check.c >/dev/null 2>&1
175 then
176 append_ldflags "$@"
177 else
- 178 return 1
+ 178 :
179 fi
180 }
```
And now I get stuck at this error:
```
Checking for specifying soname for shared lib... no
Unable to specify soname (is Darwin supported?)
```

Do you have any idea of what's going wrong? Thanks

---
*GNU bash, version 3.2.57(1)-release (x86_64-apple-darwin17)*
*but I also tried to `sh` it*