Summary:
- move toTextMateScope to SemanticHighlighting.h;
- move the buildLookupTable to LSP layer (as LSP requires such form);

Reviewers: sammccall, jvikstrom

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

Tags: #clang

Differential Revision: https://reviews.llvm.org/D64202

llvm-svn: 365135