Desugaring optimizations.  Add single-step desugaring methods to all
concrete types.  Use unqualified desugaring for getAs<> and sundry.
Fix a few users to either not desugar or use qualified desugar, as seemed
appropriate.  Removed Type's qualified desugar method, as it was easy
to accidentally use instead of QualType's.




git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@83116 91177308-0d34-0410-b5e6-96231b3b80d8
6 files changed