Compare nodes instead of symRef in SequentialStoreSimplification

SequentialStoreSimplification compares baseVar symRef to confirm stores
being to the same array for simplification. For object fields the symRef
matches even if arrays are different.

To fix the issue a node check is used instead to make sure that its
storing to the same array even if symRefs match.

runtime/compiler/optimizer/SequentialStoreSimplifier.cpp

@@ -1655,8 +1655,9 @@ bool TR_arraycopySequentialStores::insertConsistentTree()
       dumpOptDetails(comp(), " insertTree: multiplier must be 1 in aiadd tree\n");
       return false;
       }
-   TR::SymbolReference* activeBaseRef = _activeAddrTree->getBaseVarNode()->isNull() ? NULL : _activeAddrTree->getBaseVarNode()->getChild()->skipConversions()->getSymbolReference();
-   if (activeBaseRef == NULL)
+
+   TR::Node* activeBaseNode = _activeAddrTree->getBaseVarNode()->isNull() ? NULL : _activeAddrTree->getBaseVarNode()->getChild()->skipConversions();
+   if (activeBaseNode == NULL)
       {
       dumpOptDetails(comp(), " insertTree: no base variable in aiadd tree\n");
       return false;
@@ -1670,8 +1671,9 @@ bool TR_arraycopySequentialStores::insertConsistentTree()
       }
 
    // make sure the index variable and base variable is consistent with the first tree
+   TR::Node* baseNode = _addrTree[0]->getBaseVarNode()->isNull() ? NULL : _addrTree[0]->getBaseVarNode()->getChild()->skipConversions();
    TR::SymbolReference* baseRef = _addrTree[0]->getBaseVarNode()->isNull() ? NULL : _addrTree[0]->getBaseVarNode()->getChild()->skipConversions()->getSymbolReference();
-   if (baseRef != activeBaseRef)
+   if (baseNode != activeBaseNode)
       {
       dumpOptDetails(comp(), " insertTree: base variable is different than previous tree\n");
       return false;