[clangd] Remove override result handling logic from clangd
[clangd] Remove override result handling logic from clangd

Summary:
Since we plan to move handling of override suggestions to Sema with
D52225 this patch just makes sure clangd-side has no logic related to that
anymore and updates tests.

Reviewers: ioeric, ilya-biryukov

Reviewed By: ioeric

Subscribers: MaskRay, jkorous, arphaman, cfe-commits

Differential Revision: https://reviews.llvm.org/D52226

git-svn-id: a34e9779ed74578ad5922b3306b3d80a0c825546@343567 91177308-0d34-0410-b5e6-96231b3b80d8

llvm-mirror/clang-tools-extra,llvm-mirror/clang-tools-extra,llvm-mirror/clang-tools-extra,llvm-mirror/clang-tools-extra