[Clangd] Fixed SelectionTree bug for macros

Summary:
Fixed SelectionTree bug for macros
- Fixed SelectionTree claimRange for macros and template instantiations
- Fixed SelectionTree unit tests
- Changed a breaking test in TweakTests

Reviewers: sammccall, kadircet

Subscribers: ilya-biryukov, MaskRay, jkorous, arphaman, cfe-commits

Tags: #clang

Differential Revision: https://reviews.llvm.org/D64329

llvm-svn: 366566