TargetLibraryInfo: Introduce wcslen

wcslen is part of the C99 and C++98 standards.

- This introduces the function to TargetLibraryInfo.
- Also set attributes for wcslen in llvm::inferLibFuncAttributes().

Differential Revision: https://reviews.llvm.org/D32837

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@302278 91177308-0d34-0410-b5e6-96231b3b80d8
4 files changed