Fix crash w/BlockDecl and invalid qualified decl.

I'm not really satisfied with the ad-hoc nature of
Sema::diagnoseQualifiedDeclaration, but I'm not sure how to fix it.

Fixes <rdar://problem/14639501>.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@188208 91177308-0d34-0410-b5e6-96231b3b80d8
Fix pretty-printing for unnamed unions.

This is just a couple of minor fixes to account for the existence
of ElaboratedType.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@188209 91177308-0d34-0410-b5e6-96231b3b80d8