RFR: 8253447: Remove buggy code introduced by 8249451

[Jamsheed Mohammed C M]

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.

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Commit messages:
 - fixing buggy code introduced in 8249451

Changes: https://git.openjdk.java.net/jdk/pull/292/files
 Webrev: https://webrevs.openjdk.java.net/?repo=jdk&pr=292&range=00
  Issue: https://bugs.openjdk.java.net/browse/JDK-8253447
  Stats: 1 line in 1 file changed: 0 ins; 0 del; 1 mod
  Patch: https://git.openjdk.java.net/jdk/pull/292.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk pull/292/head:pull/292

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