Recommit r222044 with a test fix - it does not make sense to hunt
for a typedef before arithmetic conversion in all rare corner cases.


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@222049 91177308-0d34-0410-b5e6-96231b3b80d8
[c++1z] Support [[deprecated]] attributes on namespaces. Note that it only applies to situations where the namespace is mentioned. Thus, use on anonymous namespaces is diagnosed.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@222054 91177308-0d34-0410-b5e6-96231b3b80d8