RFR(S): 8147645: get_ctrl_no_update() code is wrong

[Roland Westrelin]

FTR, I pushed this change with a slightly different test case:

http://hg.openjdk.java.net/jdk9/hs-comp/hotspot/file/796b8077f6e6/test/compiler/loopopts/TestArraysFillDeadControl.java

The one from the review:

http://cr.openjdk.java.net/~roland/8147645/webrev.00/test/compiler/loopopts/TestArraysFillDeadControl.java.html

which was straight from the bug report would time out on windows because of the use of the graphics API.

Roland.