[libc] Clean up errno header usage in all remaining math/smoke tests. (#157565)
This is a follow-up to #157517, which fixes the remaining math/smoke
tests, and changes them to only include `hdr/errno_macros.h`, as the
tests just need the errno values to pass into `EXPECT_MATH_ERRO` macro.
A couple non-mechanical changes include:
* slightly better test coverage for some exp/log tests -- that actually
validates that errno is set to `EDOM` or `ERANGE` for certain inputs;
* explicit inclusion of `src/__support/libc_errno.h` in
RoundToIntegerTest template, which still needs to be fixed.
With this change there's a single libc_errno usage left:
```
$ grep -lrnH "libc_errno.h" test/src/math/smoke
test/src/math/smoke/RoundToIntegerTest.h
```
GitOrigin-RevId: 807ee5d1e0ce5b611ac9ab5841d2f25ca6d0a872
56 files changed
