Remove some dead code

Author: andrykonchin

src/main/java/org/truffleruby/cext/CExtNodes.java

@@ -1448,7 +1448,7 @@ protected Object debug(Object... objects) {
                         builder.append(String.format("%02x", bytes[i]));
                     }
 
-                    representation = tstring.toString() + " (" + builder.toString() + ")";
+                    representation = tstring + " (" + builder + ")";
                 } else if (RubyGuards.isRubyValue(object)) {
                     representation = object.toString() + " (" + RubyGuards.getJavaString(callToS(object)) + ")";
                 } else {

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

@@ -31,10 +31,6 @@ public WhileNode(RepeatingNode repeatingNode) {
         loopNode = Truffle.getRuntime().createLoopNode(repeatingNode);
     }
 
-    private WhileNode(LoopNode loopNode) {
-        this.loopNode = loopNode;
-    }
-
     @Override
     public Object execute(VirtualFrame frame) {
         loopNode.execute(frame);

src/main/java/org/truffleruby/language/methods/SharedMethodInfo.java

@@ -94,18 +94,6 @@ public SharedMethodInfo convertMethodMissingToMethod(RubyModule declaringModule,
                 ArgumentDescriptor.ANY);
     }
 
-    public SharedMethodInfo withArity(Arity newArity) {
-        return new SharedMethodInfo(
-                sourceSection,
-                staticLexicalScope,
-                newArity,
-                originalName,
-                blockDepth,
-                parseName,
-                notes,
-                argumentDescriptors);
-    }
-
     public SourceSection getSourceSection() {
         return sourceSection;
     }