[libclang] For a class extension, give it a unique USR but for any property or ivar
it contains give it a USR based on its semantic context, which is the interface.

This follows what we already did for objc methods. rdar://10371669

llvm-svn: 143464
4 files changed
tree: 81151cb2754ba96d64c22eebf89d9446250087a0
  1. clang/
  2. compiler-rt/
  3. debuginfo-tests/
  4. libcxx/
  5. libcxxabi/
  6. lldb/
  7. llvm/
  8. polly/