Typically with libc implementations, wchar_t and co are either defined
entirely by the libc or, under libc's arrangement, by headers supplied
by the compiler.

Things like dlmalloc in relibc need these definitions from relibc itself
and that's already already furnished by relibc's stddef.h.

These additional definitions here are redundant and collide with
compiler headers - for example: onig_sys (something that uutils depends
on) breaks. Instead, this patch makes the compiler headers define
things appropriately.

Add sys_timeb header

Based on what musl does.

wow i am stupid for writing this code

For some reason, C handles `==` before `&`.
So `a & b == c` is the same thing as `a & (b == c)`.

cbindgen can't handle negative numbers, see https://github.com/eqrion/cbindgen/issues/205

Doesn't link yet due to "multiple definitions of malloc", because some are supplied by some library of bash itself. Really odd.

I really really wish I could actually test this on redox. All I know is: it compiles