When pretty-printing tag types, only print the tag if we're in C (and

When pretty-printing tag types, only print the tag if we're in C (and
therefore not creating ElaboratedTypes, which are still pretty-printed
with the written tag).

Most of these testcase changes were done by script, so don't feel too
sorry for my fingers.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@98149 91177308-0d34-0410-b5e6-96231b3b80d8