Add (D)CHECK_IMPLIES to ART logging

Adds an _IMPLIES macro which is equivalent to checking a => b. This
CL includes an example of how it could be useful to aid
readability.

Test: art/test/testrunner/testrunner.py --host --64 --optimizing -b
Change-Id: If36ccf2a1d10ebd0b0c9f9635020dc78f5ae94ae
2 files changed