Do not modify a cl::opt programmatically, global mutable state is evil.

Found by TSAN on ThinLTO.

From: Mehdi Amini <mehdi.amini@apple.com>

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@266514 91177308-0d34-0410-b5e6-96231b3b80d8
1 file changed