Remove strong mode support from binary operations.

test/mjsunit/messages.js

 // Copyright 2015 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 // Flags: --stack-size=100 --harmony --harmony-reflect --harmony-regexps
-// Flags: --harmony-simd --strong-mode
+// Flags: --harmony-simd
 
 function test(f, expected, type) {
   try {
     f();
   } catch (e) {
     assertInstanceof(e, type);
     assertEquals(expected, e.message);
     return;
   }
   assertUnreachable("Exception expected");
@@ skipping 281 matching lines @@
 }, "'caller', 'callee', and 'arguments' properties may not be accessed on " +
    "strict mode functions or the arguments objects for calls to them",
    TypeError);
 
 // kStrictReadOnlyProperty
 test(function() {
   "use strict";
   (1).a = 1;
 }, "Cannot create property 'a' on number '1'", TypeError);
 
-// kStrongImplicitCast
-test(function() {
-  "use strong";
-  "a" + 1;
-}, "In strong mode, implicit conversions are deprecated", TypeError);
-
 // kSymbolToString
 test(function() {
   "" + Symbol();
 }, "Cannot convert a Symbol value to a string", TypeError);
 
 // kSymbolToNumber
 test(function() {
   1 + Symbol();
 }, "Cannot convert a Symbol value to a number", TypeError);
 
@@ skipping 122 matching lines @@
   Number(1).toString(100);
 }, "toString() radix argument must be between 2 and 36", RangeError);
 
 
 // === URIError ===
 
 // kURIMalformed
 test(function() {
   decodeURI("%%");
 }, "URI malformed", URIError);