RFR(S): 8040919: Uninitialised memory in hotspot/src/share/vm/compiler/oopMap.cpp

[Morris Meyer]

Folks,

Could I get a review for this parfait issue? This bit of refactoring 
courtesy of Christian Thalinger.  This change has been tested with JPRT.

Thanks much,

         --morris

JBS - https://bugs.openjdk.java.net/browse/JDK-8040919
WEBREV - http://cr.openjdk.java.net/~morris/JDK-8040919.02