Remove extra DefinedWrapperNode for ||=

Author: eregon

src/main/java/org/truffleruby/language/control/OrLazyValueDefinedNode.java

@@ -9,6 +9,8 @@
  */
 package org.truffleruby.language.control;
 
+import org.truffleruby.RubyContext;
+import org.truffleruby.RubyLanguage;
 import org.truffleruby.core.cast.BooleanCastNode;
 import org.truffleruby.language.RubyContextSourceNode;
 import org.truffleruby.language.RubyNode;
@@ -71,4 +73,8 @@ public Object execute(VirtualFrame frame) {
         }
     }
 
+    @Override
+    public Object isDefined(VirtualFrame frame, RubyLanguage language, RubyContext context) {
+        return language.coreStrings.ASSIGNMENT.createInstance(context);
+    }
 }

src/main/java/org/truffleruby/parser/BodyTranslator.java

@@ -2354,9 +2354,7 @@ public RubyNode visitOpAsgnNode(OpAsgnParseNode node) {
                     pos,
                     receiverValue.get(pos),
                     node.getVariableName() + "=",
-                    buildArrayNode(
-                            pos,
-                            node.getValueNode()),
+                    buildArrayNode(pos, node.getValueNode()),
                     false,
                     node.getReceiverNode() instanceof SelfParseNode);
 
@@ -2432,9 +2430,7 @@ private RubyNode translateOpAsgOrNode(ParseNode node, RubyNode lhs, RubyNode rhs
 
         final SourceIndexLength sourceSection = node.getPosition();
 
-        final RubyNode ret = new DefinedWrapperNode(
-                language.coreStrings.ASSIGNMENT,
-                new OrLazyValueDefinedNode(lhs, rhs));
+        final RubyNode ret = new OrLazyValueDefinedNode(lhs, rhs);
         ret.unsafeSetSourceSection(sourceSection);
         return addNewlineIfNeeded(node, ret);
     }