[libcxx-commits] [libcxx] [libc++][NFC] Refactor `[[nodiscard]]` tests (PR #173451)

[Hristo Hristov via libcxx-commits]

https://github.com/H-G-Hristov commented:

Some stuff was copied/moved from one file to another to consolidate the tests.

https://github.com/llvm/llvm-project/pull/173451