c11- Check for c11 language option as documentation says
feature is c11 about nested struct declarations must have
struct-declarator-list. Without this change, code
which was meant for c99 breaks. rdar://18125536


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@216469 91177308-0d34-0410-b5e6-96231b3b80d8