cmake: Only add -pedantic if LLVM didn't add it. Don't unconditionally add
-Wall -W, since it's already provided by LLVM's cmake config, and that
overrides fixes (such as -Wno-uninitialized) which LLVM's cmake setup may have
provided.

llvm-svn: 180018
GitOrigin-RevId: da466db02ad02b818dbbeeb6349330ca7b4a9514
1 file changed