Refactor find*Specialization functions using SpecEntryTraits

This patch reimplements the find*Specialization family of member
functions of {Class,Function}TemplateDecl in terms of a common
implementation that uses SpecEntryTraits to obtain the most recent
declaration.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@109869 91177308-0d34-0410-b5e6-96231b3b80d8
2 files changed