1. Fix a todo in Parser::ParseTag, to recover better. On code like
that in test/Sema/decl-invalid.c it causes us to return a single
error instead of multiple.
2. Fix an error in Sema::ParseDeclarator, where it would crash if the
declarator didn't have an identifier. Instead, diagnose the problem.
3. Start adding infrastructure to track the range of locations covered
by a declspec or declarator. This is mostly implemented for declspec,
but could be improved, it is missing for declarator.
Thanks to Neil for pointing out this crash.
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@40482 91177308-0d34-0410-b5e6-96231b3b80d8