llvm-project

f7e172da - [ItaniumDemangle][test] Factor demangler test-cases into file and sync into LLVM (#137947)

[ItaniumDemangle][test] Factor demangler test-cases into file and sync into LLVM (#137947) This patch turns the `libcxxabi/test/test_demangle.pass.cpp` into gtest unit-tests in `llvm/unittests/Demangle`. The main motivation for this is https://github.com/llvm/llvm-project/pull/137793, where we want to re-use the test-cases from the ItaniumDemangler to test our OutputBuffer implementation. `libcxxabi/test/test_demangle.pass.cpp` now only tests the `__cxa_demangle` API surface, not the underlying ItaniumDemangle implementation.