We'd also like for "C++11" or "c++11" to be used for the warning
groups, but without removing the old warning flags. Patches welcome;
I've run out of time to work on this today.


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@141801 91177308-0d34-0410-b5e6-96231b3b80d8