Unify our diagnostic printing for errors of the form, "we didn't like
what we found when we looked into <blah>", where <blah> is a
DeclContext*. We can now format DeclContext*'s in nice ways, e.g.,
"namespace N", "the global namespace", "'class Foo'".

This is part of PR3990, but we're not quite there yet.



git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@84028 91177308-0d34-0410-b5e6-96231b3b80d8
14 files changed