Disable simplifying j9Class to j.l.Class to j9Class

Tree Simplification recognizes an indirect load that gets a
java/lang/Class from a j9Class, and then gets the j9Class from that
java/lang/Class can be simplified to refer to the original j9Class
pointer itself.  However, that introduces an l2a operation which causes
problems for Code Generation's l2aEvaluators, as they assume that l2a
operations are only used for compressed references.  Until the two
different kinds of conversions of integers to addresses can be
distinguished from one another, this transformation in Tree
Simplification will be disabled.

Author: hzongaro

runtime/compiler/optimizer/J9Simplifier.cpp

@@ -1203,8 +1203,13 @@ J9::Simplifier::simplifyIndirectLoadPatterns(TR::Node *node)
 
          TR::SymbolReference *childSymref = firstChild->getSymbolReference();
 
+         // Temporarily disable simplification of j9class->java/lang/Class->j9class to j9class
+         // The potential introduction of an l2a is causing problems for l2aEvaluator,
+         // which makes the assumption that l2a is only used for compressed references
+#if 0
          if (symRefPairMatches(nodeSymref, childSymref, getSymRefTab()->findClassFromJavaLangClassSymbolRef(), getSymRefTab()->findJavaLangClassFromClassSymbolRef()))
             fieldsAreComplementary = true;
+#endif
 
          if (symRefPairMatches(nodeSymref, childSymref, getSymRefTab()->findClassFromJavaLangClassAsPrimitiveSymbolRef(), getSymRefTab()->findJavaLangClassFromClassSymbolRef()))
             fieldsAreComplementary = true;