Minor in JS AST: drop unused constructors from JsBinaryOperation, JsUnaryOperation, JsPrefixOperation and JsPostfixOperation.

js/js.dart-ast/src/com/google/dart/compiler/backend/js/ast/JsBinaryOperation.java

@@ -15,10 +15,6 @@ public final class JsBinaryOperation extends JsExpressionImpl {
     @NotNull
     private final JsBinaryOperator op;
 
-    public JsBinaryOperation(@NotNull JsBinaryOperator op) {
-        this(op, null, null);
-    }
-
     public JsBinaryOperation(@NotNull JsBinaryOperator op, @Nullable JsExpression arg1, @Nullable JsExpression arg2) {
         this.op = op;
         this.arg1 = arg1;

js/js.dart-ast/src/com/google/dart/compiler/backend/js/ast/JsPostfixOperation.java

@@ -8,10 +8,6 @@ import com.google.dart.compiler.util.AstUtil;
 import org.jetbrains.annotations.NotNull;
 
 public final class JsPostfixOperation extends JsUnaryOperation {
-  public JsPostfixOperation(JsUnaryOperator op) {
-    this(op, null);
-  }
-
   public JsPostfixOperation(JsUnaryOperator op, JsExpression arg) {
     super(op, arg);
   }

js/js.dart-ast/src/com/google/dart/compiler/backend/js/ast/JsPrefixOperation.java

@@ -8,10 +8,6 @@ import com.google.dart.compiler.util.AstUtil;
 import org.jetbrains.annotations.NotNull;
 
 public final class JsPrefixOperation extends JsUnaryOperation {
-    public JsPrefixOperation(JsUnaryOperator op) {
-        this(op, null);
-    }
-
     public JsPrefixOperation(JsUnaryOperator op, JsExpression arg) {
         super(op, arg);
     }

js/js.dart-ast/src/com/google/dart/compiler/backend/js/ast/JsUnaryOperation.java

@@ -10,10 +10,6 @@ public abstract class JsUnaryOperation extends JsExpressionImpl {
 
     private final JsUnaryOperator op;
 
-    public JsUnaryOperation(JsUnaryOperator op) {
-        this(op, null);
-    }
-
     public JsUnaryOperation(JsUnaryOperator op, JsExpression arg) {
         super();
         this.op = op;