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)`.

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

Remove the broken Rust functions and instead provide C macros in a
`include/bits` header. The C macros were taken from musl.