DebugInfo: Remove DIType

This is the last major parent class, so I'll probably start deleting
classes in batches now.  Looks like many of the references to the DI*
hierarchy were updated organically along the way.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@235331 91177308-0d34-0410-b5e6-96231b3b80d8
6 files changed