hg: graal/graal: handle null in HotSpotzreferenceMap.getFrameMap()|getRegisterMap()

[doug.simon at oracle.com]

Changeset: 72d0cd2eeca4
Author:    Doug Simon <doug.simon at oracle.com>
Date:      2014-12-14 13:43 +0100
URL:       http://hg.openjdk.java.net/graal/graal/rev/72d0cd2eeca4

handle null in HotSpotzreferenceMap.getFrameMap()|getRegisterMap()

! graal/com.oracle.graal.hotspot/src/com/oracle/graal/hotspot/HotSpotReferenceMap.java