[clang] [runtimes] Fix parsing of LIB{CXX, CXXABI, UNWIND}_TEST_PARAMS (PR #67691)

[Vladimir Vereschaka via cfe-commits]

vvereschaka wrote:

@ldionne @arichardson ,
the problem is still there for more than 10 days already. Do you guys plan to fix it!

https://github.com/llvm/llvm-project/pull/67691