Make sure constantIndexing2 is optimized with DEOPT.

Rationale:
This particular method is also used in foo() to see if
assertIsManaged() holds after going out of bounds.
During my last rewrite (which added a driver to make
sure more code is actually executed), I changed the
method to show a non-deopt case. However, that would
miss this test. I moved the non-deopt case into a new test.

Change-Id: Iaf3e77e33a82ff6cd300753f9e5211529353401c