Add NAME_MAX for Linux (like)

[Thomasdezeeuw]

Description

Adds NAME_MAX for Linux (like) systems.

Sources

• Linux: https://github.com/torvalds/linux/blob/9094662f6707d1d4b53d18baba459604e8bb0783/include/uapi/linux/limits.h#L12
• Musl: https://github.com/bminor/musl/blob/1b76ff0767d01df72f692806ee5adee13c67ef88/include/limits.h#L45

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