RFR(S): 8205515: assert(opcode == Op_RangeCheck) failed: no other if variant here

[Roland Westrelin]

http://cr.openjdk.java.net/~roland/8205515/webrev.00/

Profile predicates try to apply predication to a CountedLoopNodeEnd
that's produced as a result of peeling (so it's no longer a true end of
loop node). I added the same check that regular predication performs.

Also, I noticed I forgot to check for Reason_profile_predicate in
dominated_by() methods. I couldn't get a test case that would fail
because of that (I can get a load node that doesn't depend on the right
predicate anymore but the load node is scheduled too late for the test
to fail). I included the fix here. Or do I need another bug for this?

Roland.