Hide the specializations folding sets of ClassTemplateDecl as an implementation detail (InsertPos
leaks though) and add methods to its interface for adding/finding specializations.

Simplifies its users a bit and we no longer need to replace specializations in the folding set with
their redeclarations. We just return the most recent redeclarations.

As a bonus, it fixes http://llvm.org/PR7670.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@108832 91177308-0d34-0410-b5e6-96231b3b80d8
5 files changed