[PM] Finish removing references to fix MSVC builds. Somehow adding base

[PM] Finish removing references to fix MSVC builds. Somehow adding base
classes changed whether the decltype of these expressions was
a reference. I'm somewhat horrified why, and there may need to be
a deeper fix on MSVC, but this should at least get the bots a step
further.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@262008 91177308-0d34-0410-b5e6-96231b3b80d8