Re-apply r194300 with fixes for warnings.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@194311 91177308-0d34-0410-b5e6-96231b3b80d8
Fix whitespace.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@194313 91177308-0d34-0410-b5e6-96231b3b80d8
include/llvm/CodeGen/PBQP: Update @param(s) in comments. [-Wdocumentation]

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@194314 91177308-0d34-0410-b5e6-96231b3b80d8