RFR(XS) 8163313: assert(comp != __null) failed: compiler not available

[Igor Veresov]

WB_IsIntrinsicAvailable() needs additional check that the compLevel in the request is less than CompLevel_highest_tier. It actually was this way before JDK-8162881 (http://hg.openjdk.java.net/jdk9/hs-comp/hotspot/rev/a2e73f79284b), but then it was change to check only for TieredStopAtLevel. But the former is not necessarily less or equal to CompLevel_highest_tier, which in client VM leads to a failure when asking the question about higher levels.

Webrev: http://cr.openjdk.java.net/~iveresov/8163313/webrev.00/

igor