mingw,musl,wasi-libc: remove c files, that only provide functions already included in zigc
mingw: remove c files, that only provide functions, which are in ucrt
mingw: do not include mingw files/zigc functions on targets on which they in ucrt
Seems like it was missed when implementing `rint`.
This was checked by running:
```
$ ./build/stage3/bin/zig build -p stage4 -Denable-llvm -Dno-lib
$ stage4/bin/zig build test-libc -Dlibc-test-path=<LIBC-TEST-PATH> -Dtest-filter=rint -fqemu -fwasmtime --summary line
Build Summary: 2209/2209 steps succeeded
```
The implementation was ported from `musl` to Zig code, and the `rint`
unit tests were generalized so they could be used for `rintf` as well.
This was checked both through unit tests and running `libc-test` suite:
```
$ ./build/stage3/bin/zig build -p stage4 -Denable-llvm -Dno-lib
$ stage4/bin/zig build test-libc -Dlibc-test-path=<LIBC-TEST-PATH> -Dtest-filter=rintf -fqemu -fwasmtime --summary line
Build Summary: 1657/1657 steps succeeded
```
The behaviour of `libc` `finite` functions is the same as Zig std's, so
the function basically delegates to `math.isFinite` and no new tests were
added. These functions are obsolete, but still part of `musl`.
No results are attached in this case as `libc-test` doesn't have tests for them.
The `frexp` implementation was generalized so it can be used for `f32`
and `c_longdouble` types as well.
The changes were tested by running:
```
$ ./build/stage3/bin/zig build -p stage4 -Denable-llvm -Dno-lib
$ stage4/bin/zig build test-libc -Dlibc-test-path=<LIBC-TEST-PATH> -Dtest-filter=frexp -fqemu -fwasmtime --summary line
Build Summary: 737/737 steps succeeded
$ stage4/bin/zig build test-libc -Dlibc-test-path=<LIBC-TEST-PATH> -Dtest-filter=frexpf -fqemu -fwasmtime --summary line
Build Summary: 369/369 steps succeeded
```
The changes were tested by running:
```
$ ./build/stage3/bin/zig build -p stage4 -Denable-llvm -Dno-lib
$ stage4/bin/zig build test-libc -Dlibc-test-path=<LIBC-TEST-PATH> -Dtest-filter=frexp -fqemu -fwasmtime --summary line
Build Summary: 737/737 steps succeeded
```
The tests were passing even when it was a straightforward calling of Zig
std library, but I wanted the `x is NaN` special case to match the
behaviour described in `libc` manpages, and for it to be consistent
with how infinities as arguments are handled in Zig.
`modf` function was generalized and renamed to `modfGeneric`, `modf` and
`modff` provide the appropriate type while calling that function. The
unit tests were also generalized so they can be reused for different
float types.
Both `modf` and `modff` were tested after making these changes:
```
$ stage4/bin/zig build test-libc -Dlibc-test-path=<LIBC-TEST-PATH> -Dtest-filter=modf -fqemu -fwasmtime --summary line
Build Summary: 921/921 steps succeeded
```
```
stage4/bin/zig build test-libc -Dlibc-test-path=<LIBC-TEST-PATH> -Dtest-filter=modff -fqemu -fwasmtime --summary line
Build Summary: 369/369 steps succeeded
```
The behaviour regarding special cases differs between `libc` and Zig's
`stdlib` for `modf`, so the implementation couldn't be a straightforward
calling of `stdlib` function.
Other than the obvious documented differences, I also had problems with
the `INVALID` flag being raised while running `libc-test` suite on riscv
arch through qemu. The solution was to test if the argument is `NaN`,
and then return a quiet `NaN` if so.
Passing tests, that should include all the special cases to be wary of,
were also added.
Test results:
```
$ stage4/bin/zig build test-libc -Dlibc-test-path=<LIBC-TEST-PATH> -Dtest-filter=modf -fqemu -fwasmtime --summary line
Build Summary: 921/921 steps succeeded
```
The functions were sorted alphabetically for easier navigation, and less
confusion where to add a new one. The sorting of comptime exports was
done within the visual "blocks".
Since this is my first time contributing I wanted to keep it simple and I added just one function
I tested with
```bash
stage3/bin/zig build -p stage4 -Dno-lib -Dno-langref -Denable-llvm=true --search-prefix ~/repos/zig-boostrap/out/native-linux-musl-baseline/
stage4/bin/zig build test-libc -Dlibc-test-path=../libc-test -Dtest-target-filter=x86_64-linux-musl
```
and the tests passed.
I'm planning on doing more once I get the hang of it.
Co-authored-by: david <davidc.fried@gmail.com>
Reviewed-on: https://codeberg.org/ziglang/zig/pulls/30888
Reviewed-by: Andrew Kelley <andrew@ziglang.org>
Co-authored-by: Daggerfall-is-the-best-TES-game <daggerfall-is-the-best-tes-game@noreply.codeberg.org>
Co-committed-by: Daggerfall-is-the-best-TES-game <daggerfall-is-the-best-tes-game@noreply.codeberg.org>
David Rubin