* Also introduces ImportTemplateArgumentListInfo facility (A. Sidorin)

This re-commits r320942 after fixing the behaviour on '-fdelayed-template-parsing'
option and adding additional checks.

Patch by Peter Szecsi!

Differential Revision: https://reviews.llvm.org/D38692


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@321492 91177308-0d34-0410-b5e6-96231b3b80d8