[clang-tidy] Update `TransformerClangTidyCheck` to use new `buildMatchers` functionality.

Summary:
`buildMatchers` is the new, more general way to extract the matcher from a rule.
This change migrates the code to use it instead of `buildMatcher`.

Reviewers: gribozavr

Subscribers: xazax.hun, cfe-commits

Tags: #clang

Differential Revision: https://reviews.llvm.org/D65879

llvm-svn: 368700