Mass rename C1x references to C11. The name hasn't proliferated like "C++0x" so this patch is surprisingly small.

Also drop -Wc1x-extensions in favor of -Wc11-extensions. I don't think we need to keep this around for compatibility.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@147221 91177308-0d34-0410-b5e6-96231b3b80d8
22 files changed