Refactor DynTypedMatcher into a value type class, just like Matcher<T>.

Summary:
Refactor DynTypedMatcher into a value type class, just like Matcher<T>.
This simplifies its usage and removes the virtual hierarchy from Matcher<T>.
It also enables planned changes to replace MatcherInteface<T>.
Too many instantiaions of this class hierarchy has been causing Registry.cpp.o to bloat in size and number of symbols.

Reviewers: klimek

CC: cfe-commits, revane

Differential Revision: http://llvm-reviews.chandlerc.com/D1661

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@193100 91177308-0d34-0410-b5e6-96231b3b80d8