Hello!

TCC's custom `stddef.h` header seems to break under Alpine Linux aarch64, which uses musl.

The full error is

/usr/local/lib/tcc/include/stddef.h:6: error: Incompatible redefinition of 'wchar_t'

The system's `wchar_t` is defined in `/usr/include/bits/alltypes.h` as

typedef unsigned wchar_t;

So I tried to change `__WCHAR_TYPE` to `unsigned` in `tccdefs.h`, but TCC still throws the error.

The obvious solution would be removing TCC's custom headers and using the system ones downstream, but I wonder if there would be a way to fix this upstream?

Thanks,
Álvaro.