Convert InstantiationInfo and much of the related code to ExpansionInfo
and various other 'expansion' based terms. I've tried to reformat where
appropriate and catch as many references in comments but I'm going to do
several more passes. Also I've tried to expand parameter names to be
more clear where appropriate.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@136056 91177308-0d34-0410-b5e6-96231b3b80d8
4 files changed