RFR: 8253447: Remove buggy code introduced by 8249451

[Jamsheed Mohammed C M]

On Tue, 22 Sep 2020 01:48:53 GMT, Jamsheed Mohammed C M <jcm at openjdk.org> wrote:

> if ((thread->has_pending_exception() || thread->frames_to_pop_failed_realloc() > 0) && exec_mode !=
> Unpack_uncommon_trap) {
>     assert(thread->has_pending_exception(), "should have thrown OOME/Async");
> 
> introduced a buggy code checking, clearing pending exception and taking Unpack_exception route.
> 
> This can have consequences as the deopt entries may have additional logic depending on bci's. and the change introduced
> in 8249451 doesn't honor deopt exception checking and forward logic. Thank you @fisk  for pointing the bug in the code.
> Request for review.

@dholmes-ora @veresov @fisk  could you please have a look.

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PR: https://git.openjdk.java.net/jdk/pull/292