8031401: Remove unused code in the reference processor
Summary: Assume pending_list uses discovered field and remove resulting dead code.
Reviewed-by: brutisso, pliden
8073669: gc/TestSoftReferencesBehaviorOnOOME.java times out in nightlies
Summary: changed test scenario to more straight-forward one, added tricks to prevent compiler optimizations and added checks when OOME didn't thrown as expected.
Reviewed-by: tschatzl, jwilhelm