Add detailed checking of reference counts in testAssignmentAndCopyCrossTypes
Add detailed checking of reference counts in testAssignmentAndCopyCrossTypes

Summary:
Following diff broke this test. Making the test stricter so
that 1) it's easier to debug 2) we can be confident that changes to
the test are properly attributed to pieces of the test rather than
just correcting the end totals.

Reviewed By: dreiss

Differential Revision: D19231409

fbshipit-source-id: 73057c6398ca7827b364dfc6489cc174620bc8bc

facebookincubator/fbjni,facebookincubator/fbjni,facebookincubator/fbjni,facebookincubator/fbjni