Keep track of type source information in the return type of an

Objective-C method declaration, e.g., for 

  - (Foo *)myMethod;

we now have TypeSourceInfo for the Foo*.



git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@97942 91177308-0d34-0410-b5e6-96231b3b80d8