[clang] [clang][bytecode] Avoid crash in constexpr wcslen on invalid argument… (PR #177891)

[Ayush Kumar Gaur via cfe-commits]

Ayush3941 wrote:

my bad i am new here 
added a test at clang/test/AST/ByteCode/interp_builtin_wclen.cpp

https://github.com/llvm/llvm-project/pull/177891