Use dex2oat instead of dex2oatd in non-debug run-tests.

The "$inline$" and "$noinline$" substrings in methods' names are now
always honored when compiling with a core image, regardless of the
debug mode status.

Test: art/test/testrunner/testrunner.py --ndebug --debug
Change-Id: I3c3e0fb9c33644093bb5fb218180b68dcc10fc83