[AST] Fix the EndLoc calculation for ObjCObjectPointer

There is an issue where the AST code does not compute the correct SourceRange
for a ObjCObjectPointer.

From Richard Smith (ie @zygoloid) in discord:

I think the problem is that we set an invalid location for the * (because there
isn't one): https://github.com/llvm/llvm-project/blob/main/clang/lib/Sema/SemaType.cpp#L1121
And then we use the default getLocalSourceRangeImpl for a PointerLikeTypeLoc
that just assumes the * location is the type's end location:
https://github.com/llvm/llvm-project/blob/main/clang/include/clang/AST/TypeLoc.h#L1293
Possibly we should be special-casing that here:
https://github.com/llvm/llvm-project/blob/main/clang/lib/AST/TypeLoc.cpp#L228

My change:

introduces a AST dump test to show the issue in the first commit
special cases ObjCObjectPointerType in the second commit to correctly compute
the end location