linux: add missing pthread_attr_setstack

[terohuttunen]

Description

This PR adds the missing pthread_attr_setstack function for linux-like architectures. The getter pthread_attr_getstack is already defined.

Sources

• pthread_attr_setstack man page

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]

r? @tgross35

rustbot has assigned @tgross35.
They will have a look at your PR within the next two weeks and either review your PR or reassign to another reviewer.

Use r? to explicitly pick a reviewer