ObjectiveC: Refactor applyObjCProtocolQualifiers.
To construct the canonical type of ObjCTypeParamType, we need to apply
qualifiers on ObjCObjectPointerType. The updated applyObjCProtocolQualifiers
handles this case by merging the protocol lists, constructing a new
ObjCObjectType, then a new ObjCObjectPointerType.
rdar://
24619481
rdar://
25060179
Differential Revision: http://reviews.llvm.org/D24059
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@281353
91177308-0d34-0410-b5e6-
96231b3b80d8