Use performTransformation() for VP VFT load folding

This is an optional transformation, and when it is performed, tracing
should dump trees after the pass even if there were no other
transformations.

compiler/optimizer/VPHandlers.cpp

@@ -463,8 +463,19 @@ static bool tryFoldCompileTimeLoad(
             if (vp->comp()->compileRelocatableCode() && !vp->comp()->getOption(TR_UseSymbolValidationManager) && (vp->comp()->target().cpu.isPower() || fej9->getClassLoader(clazz) != fej9->getSystemClassLoader()))
                return false;
 #endif
-            if (vp->trace())
-               traceMsg(vp->comp(), "VP Transforming VFTLoad to loadaddr: as n%dn is VFT load of known class", node->getGlobalIndex());
+            // performTransformation() is needed here but not in the other cases
+            // because transformIndirectLoadChain[At]() does one internally.
+            if (!performTransformation(
+                  vp->comp(),
+                  "%sTransforming VFT load n%un [%p] to loadaddr "
+                  "based on the fixed type of n%un [%p]\n",
+                  OPT_DETAILS,
+                  node->getGlobalIndex(),
+                  node,
+                  curNode->getGlobalIndex(),
+                  curNode))
+               return false;
+
             node->setNumChildren(0);
             TR::Node::recreateWithSymRef(node, TR::loadaddr, vp->comp()->getSymRefTab()->findOrCreateClassSymbol(vp->comp()->getMethodSymbol(), -1, clazz));
             node->setFlags(0);