Remove assertion that uses deprecated Truffle API

(cherry picked from commit c177142)

Author: steve-s

com.oracle.truffle.r.nodes/src/com/oracle/truffle/r/nodes/access/variables/ReadVariableNode.java

@@ -837,7 +837,7 @@ public static RArgsValuesAndNames lookupVarArgs(Frame variableFrame) {
     }
 
     private static Object getValue(boolean[] seenValueKinds, Frame variableFrame, FrameSlot frameSlot) {
-        assert variableFrame.getFrameDescriptor() == frameSlot.getFrameDescriptor();
+        assert variableFrame.getFrameDescriptor().getSlots().contains(frameSlot) : frameSlot.getIdentifier();
         Object value = variableFrame.getValue(frameSlot);
         if (variableFrame.isObject(frameSlot)) {
             value = FrameSlotChangeMonitor.getValue(frameSlot, variableFrame);
@@ -853,7 +853,7 @@ private static Object getValue(boolean[] seenValueKinds, Frame variableFrame, Fr
     }
 
     static Object profiledGetValue(boolean[] seenValueKinds, Frame variableFrame, FrameSlot frameSlot) {
-        assert variableFrame.getFrameDescriptor() == frameSlot.getFrameDescriptor();
+        assert variableFrame.getFrameDescriptor().getSlots().contains(frameSlot) : frameSlot.getIdentifier();
         try {
             if (seenValueKinds[FrameSlotKind.Object.ordinal()] && variableFrame.isObject(frameSlot)) {
                 return FrameSlotChangeMonitor.getObject(frameSlot, variableFrame);

com.oracle.truffle.r.runtime/src/com/oracle/truffle/r/runtime/env/frame/FrameSlotChangeMonitor.java

@@ -776,8 +776,7 @@ private static synchronized FrameSlot findOrAddFrameSlot(FrameDescriptor fd, Obj
      * @param invalidateProfile Used to guard the invalidation code.
      */
     private static void checkAndInvalidate(Frame curFrame, FrameSlot slot, boolean isNonLocal, BranchProfile invalidateProfile) {
-        assert curFrame.getFrameDescriptor() == slot.getFrameDescriptor();
-
+        assert curFrame.getFrameDescriptor().getSlots().contains(slot) : slot.getIdentifier();
         if (getNotChangedNonLocallyAssumption(slot).isValid()) {
             // Check whether current frame is used outside a regular stack
             if (isNonLocal || RArguments.getIsIrregular(curFrame)) {