ART: Change behavior for rethrowing init failures (2)

Always store the pending exception when making a class erroneous.
Instead of filtering by ExceptionInInitializerError, add an option
to the rethrow that enforces a NoClassDefFoundError, which is required
by the specification.

Use the libcore companion change to add the stored error (if any) as
a cause to the NoClassDefFoundError, which should significantly help
tracking down issues.

Fix run-test 008 to expect spec-compliant behavior. Test that a cause
has been set.

Bug: 25445103
Change-Id: I6a0dc54e78312283faf23415887eff387531407f