[compiler-rt] [compiler-rt][asan] Add wcscpy/wcsncpy; enable wcscat/wcsncat on Windows (PR #160493)

[Thurston Dang via llvm-commits]

thurstond wrote:

> Hi! First-time contributor here. Could a maintainer please approve CI workflows (Build and Test Linux/Windows) to run? This PR only touches compiler-rt/asan and tests; no changes under .github/workflows. Thanks!

Done. Please fix the CI findings:
- https://github.com/llvm/llvm-project/actions/runs/17974394914/job/51153848276?pr=160493
- https://github.com/llvm/llvm-project/actions/runs/17974394872/job/51153848095?pr=160493#logs

https://github.com/llvm/llvm-project/pull/160493