[clang-query] Use the new API for named values from the Parser.

Summary: This finishes the support for autocomplete for user defined values..

Reviewers: pcc

Subscribers: cfe-commits

Differential Revision: http://reviews.llvm.org/D4851

git-svn-id: https://llvm.org/svn/llvm-project/clang-tools-extra/trunk@215474 91177308-0d34-0410-b5e6-96231b3b80d8