[ASTMatchers] Allow hasName() to look through inline namespaces

[ASTMatchers] Allow hasName() to look through inline namespaces

Summary:
Allow hasName() to look through inline namespaces.
This will fix the interaction between some clang-tidy checks and libc++.

libc++ defines names in an inline namespace named std::<version_#>.
When we try to match a name using hasName("std::xxx") it fails to match and the clang-tidy check does not work.

Reviewers: klimek

Subscribers: klimek, cfe-commits

Differential Revision: http://reviews.llvm.org/D15506

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@259898 91177308-0d34-0410-b5e6-96231b3b80d8