[clang] [clang][bytecode] Implement __builtin_{wcscmp, wcsncmp} (PR #132723)

[Rainer Orth via cfe-commits]

rorth wrote:

This patch broke the [Solaris/sparcv9 bot](https://lab.llvm.org/buildbot/#/builders/13/builds/6151).

https://github.com/llvm/llvm-project/pull/132723