Add TemplateArgument related matchers to the registry.

Summary:
Continue adding more matchers to the dynamic registry.
This time, we add TemplateArgument matchers.

Reviewers: klimek

CC: cfe-commits, revane

Differential Revision: http://llvm-reviews.chandlerc.com/D1166

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@186514 91177308-0d34-0410-b5e6-96231b3b80d8