[modules] When loading a template specialization, re-canonicalize its template

arguments because the reloaded form might have become non-canonical across the
serialization/deserialization step (this particularly happens when the
canonical form of the type involves an expression).


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@244409 91177308-0d34-0410-b5e6-96231b3b80d8