6765804: GC "dead ratios" should be unsigned Reviewed-by: ysr, tonyp

Merge

6773078: UseCompressedOops: assert(kid == 0L || s->_leaf->in(0) == 0L,"internal operands have no control") Summary: Don't set the control edge of a klass load node. Reviewed-by: never

6766316: assert(!nocreate,"Cannot build a phi for a block already parsed.") Summary: Don't use the invariant local information if there are irreducible loops. Reviewed-by: never