Implements hypotf and hypotl for libzigc #30978.

Continuation of #31104

Commands i run:

```
$ stage3/bin/zig build -p stage4 -Denable-llvm -Dno-lib

$ stage4/bin/zig build test-libc -Dlibc-test-path=../../libc-test -Dtest-filter=hypotf -fqemu -fwasmtime --summary line
Build Summary: 365/369 steps succeeded (4 skipped)

$ stage4/bin/zig build test-modules -Dtest-target-filter=windows -Dtest-filter=hypotf --summary line
Build Summary: 53/101 steps succeeded (48 skipped)
```

Reviewed-on: https://codeberg.org/ziglang/zig/pulls/31150
Reviewed-by: Andrew Kelley <andrew@ziglang.org>
Co-authored-by: Pivok <pivoc@protonmail.com>
Co-committed-by: Pivok <pivoc@protonmail.com>