[clang] [llvm] [Clang] Fix assertion failure when passing wide string literal to __builtin_nanf (PR #205452)

[Corentin Jabot via cfe-commits]

https://github.com/cor3ntin commented:

Please move the new tests you added to single-line new files to builtin-nan-wide-string.c.

https://github.com/llvm/llvm-project/pull/205452