[libclang] indexing: for a synthesized property reference have the parent be...

[libclang] indexing: for a synthesized property reference have the parent be the ObjC implementation decl.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@260253 91177308-0d34-0410-b5e6-96231b3b80d8