RFR(S): 8043125: compiler/types/correctness/CorrectnessTest.java: assert(layout->tag() == DataLayout::speculative_trap_data_tag) failed: wrong type

[Roland Westrelin]

I'm withdrawing this RFR. Igor V. pointed that there's no way an already
translated SpeculativeTrapData or a SpeculativeTrapData that is being
translated could go away. After further investigation, I found that this
bug is actually caused by a WB api call that the test uses. That WB api
call triggers a VM operation that unconditionally cleans all profile
entries. If there's a compilation on the fly, a safepoint may happen
during SpeculativeTrapData translation and entries being translated are
then removed. This really is a WB api bug.

Some of the changes in this RFR are valid anyway and make the code more
robust and I'll send them for review in a different RFR under another
bug.

Roland.