Minor cleanup in thrift/conformance
Minor cleanup in thrift/conformance

Summary:
- TypedAnySerializer functions must be const.
- Sort targets in TARGETS
- Add missing testing-test target.

Reviewed By: yfeldblum

Differential Revision: D23383684

fbshipit-source-id: 221cb60396daa472729760dd361a35f1b5bc153d

facebook/fbthrift,facebook/fbthrift,facebook/fbthrift,facebook/fbthrift,facebook/fbthrift,facebook/fbthrift,facebook/fbthrift,facebook/fbthrift,facebook/fbthrift