Add CXXCtorInitializer related matchers to the dynamic matcher registry.

Summary: Now that CXXCtorInitializer is already supported in ASTNodeKind, add CXXCtorInitializer matchers to the dynamic matcher registry.

Reviewers: klimek

CC: cfe-commits, revane

Differential Revision: http://llvm-reviews.chandlerc.com/D1158

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@186508 91177308-0d34-0410-b5e6-96231b3b80d8