Request for reviews (M): 7160161: Missed safepoint in non-Counted loop

[Vladimir Kozlov]

http://cr.openjdk.java.net/~kvn/7160161/webrev

7160161: Missed safepoint in non-Counted loop

Loop peeling optimization removes needed safepoints from peeled iteration of 
inner non-counted loop during OSR compilation. As result the path without 
safepoints is created in outer loop.

Do not remove safepoints during peeling optimization. Improve the code in 
IdealLoopTree::counted_loop() to eliminate all others safepoints in a loop (but 
not in this loop's nested loops) which have a safepoint on dominating path.

Tested with provided test case, CTW, jtreg Compiler. Did analysis of code 
generated for nested loops which are not counted.

Thanks,
Vladimir