[clang][IFS][test] Fixing lit test breakages on macOS due to r374798

Adding the quotes breaks tests because on Darwin the name mangling is prefixed
with an underscore.


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@374805 91177308-0d34-0410-b5e6-96231b3b80d8
2 files changed