RFR(L): 8203197: C2: consider all paths in loop body for loop predication

[Roland Westrelin]

Hi Nils,

Thanks for reviewing and testing this.

> Test: open/test/hotspot/jtreg/serviceability/sa/TestPrintMdo.java and ./ClhsdbCDSCore.java fails. You have added one more trap reason, but it misses a name.
>
> vmStructs_jvmci.cpp misses _header._struct._trap. It doesn't break 
> anything since the bits aren't used by any jvmci consumer, but they 
> should be there for completeness.

I will fix those.

Roland.