Fix valgrind-test-art-host-gtest-object_test.

This had been failing with the error message:

object_test F  2360  2360 art/runtime/gc/heap-inl.h:139] Check failed: !running_on_valgrind_

Then, this failing DCHECK was removed in a refactoring in
cbb2d20bea2861f244da2e2318d8c088300a3710, I believe.

This change adds back a DCHECK that's equivalent to the old one and
fixes ObjectTest.CheckAndAllocArrayFromCode by replacing a
CheckAndAllocArrayFromCode call with a
CheckAndAllocArrayFromCodeInstrumented call.

Bug: 11670287
Change-Id: Ica2f707b9a9ff48ef973b9e326a4d9786c1781f8
2 files changed