review (S) for 6927049: assert(is_Loop(),"invalid node class")

[Tom Rodriguez]

http://cr.openjdk.java.net/~never/6927049

6927049: assert(is_Loop(),"invalid node class")
Reviewed-by:

The loop predication code is missing a guard for is_Loop since it's
possible that the loop might simply by a Region if there are
irreducible loops in the loop tree.  I also moved the other loop type
guards up so they would be together before any traps count logic.
Tested with failing test from report.

src/share/vm/opto/loopTransform.cpp