[clang][DependencyScanning] Add Test Coverage of `StabeDirs` during By-Name Lookups#168143

qiongsiwu merged 2 commits intollvm:mainllvm/llvm-project:mainfrom

qiongsiwu:eng_136303612_stable_dir_testingqiongsiwu/llvm-project:eng_136303612_stable_dir_testingCopy head branch name to clipboard