fix: fix differing bitwidth types/routines under Windows x86 GNU

[dybucc]

Description

Until #5032, whenever libc was running under Windows x86 with GNU, the default
bit-width of time_t values was 32-bits. This doesn't quite align with the defaults in MSVC and
mingw, but that's been addressed in that PR.

This PR is a quick patch for stable, as the changes in #5032 are not
backwards-compatible. It separates the routines that under Windows use time_t values and changes
their link-time symbols to the 32-bit variants exposed in both MSVC and mingw, for the affected
target platform/environment.

It also adds a test, akin to the one in #5032, that should ensure the correct
bit-widths are in use for both the types and the linked routine symbols.

Note that if both #5062 and this PR are to be merged, it's preferable to merge first #5062, as this
PR will then incorporate support for the cfg introduced in that PR.

Sources

None. If any, the same as #5032 as this stems from it.

Checklist

• Relevant tests in libc-test/semver have been updated
• No placeholder or unstable values like *LAST or *MAX are included (see
  #3131)
• Tested locally (cd libc-test && cargo test --target mytarget);
  especially relevant for platforms that may not be checked in CI

@rustbot label +stable-nominated

[rustbot]

This PR was rebased onto a different main commit. Here's a range-diff highlighting what actually changed.

Rebasing is a normal part of keeping PRs up to date, so no action is needed—this note is just to help reviewers.