[gn build] Add some llvm/tools: bugpoint, dsymutil, llvm-opt-report

Also add build file for dependency llvm/lib/OptRemarks.

Needed for check-llvm.

Differential Revision: https://reviews.llvm.org/D56192


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@350217 91177308-0d34-0410-b5e6-96231b3b80d8
5 files changed