Prevent commoning conversion to address operations in LocalCSE

OMR::LocalCSE::canBeAvailable was restricting l2a operations from being
commoned to reduce the likelihood that a register holding the result of
such an operation would be marked as a collected reference and kept live
across a GC point by l2aEvaluator.  To be safest, all conversion to
address types should be similarly prevented from being commoned.

compiler/optimizer/OMRLocalCSE.cpp

@@ -1186,7 +1186,7 @@ bool OMR::LocalCSE::canBeAvailable(TR::Node *parent, TR::Node *node, TR_BitVecto
    if (node->getOpCodeValue() == TR::allocationFence)
       return false;
 
-   if (node->getOpCodeValue() == TR::l2a)
+   if (node->getOpCode().isConversion() && node->getOpCode().isRef())
       return false;
 
    if (node->getOpCode().isLoadReg() || node->getOpCode().isStoreReg() || (node->getOpCodeValue() == TR::PassThrough && parent->getOpCodeValue() != TR::GlRegDeps) || (node->getOpCodeValue() == TR::GlRegDeps))