Do not deopt when using AOT inline caches

Generating a deopt does not ensure that we will actually capture the new
types; and the danger is that we could be stuck in a loop with "forever"
deoptimizations. For example, if the method never becomes hot again, the
inline cache will not be updated and the AOT code will keep
deoptimizing.

This is a compromise because we will most likely never update the inline
cache (unless there's another reason to deopt). So we might be stuck
with a sub-optimal inline cache. As a TODO, we could be smarter when
capturing inline caches to mitigate this. (e.g. by having different
thresholds for new and old methods).

Delete test 644 which was testing a regression involving deopts which is
no longer applicable.

Bug: 38412648
Test: m test-art-host
Change-Id: Ib84559e84f07ec976feeb3a3120fa486d5bee3bf