Summary:
This adds semantic selection to the LSP Server.
Adds support for serialization of input request and the output reply.
Also adds regression tests for the feature.
Currently we do not support multi cursor.The LSP Server only accepts single position in the request as opposed to many position in the spec.
Spec:
https://github.com/microsoft/language-server-protocol/blob/dbaeumer/3.15/specification.md#textDocument_selectionRange
Reviewers: hokein
Subscribers: ilya-biryukov, MaskRay, jkorous, arphaman, kadircet, cfe-commits
Tags: #clang
Differential Revision: https://reviews.llvm.org/D67720
llvm-svn: 372753