[strong] Disallow implicit conversions for binary arithmetic operations

test/cctest/compiler/test-js-context-specialization.cc

 // Copyright 2014 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.
 
 #include "src/compiler/js-context-specialization.h"
 #include "src/compiler/js-operator.h"
 #include "src/compiler/node-matchers.h"
 #include "src/compiler/node-properties.h"
 #include "src/compiler/source-position.h"
 #include "test/cctest/cctest.h"
@@ skipping 196 matching lines @@
                            const_context, const_context, effect_in);
 
 
     Node* value_use = t.NewNode(t.simplified()->ChangeTaggedToInt32(), load);
     Node* other_load = t.NewNode(t.javascript()->LoadContext(0, slot, true),
                                  param_context, param_context, load);
     Node* effect_use = other_load;
     Node* other_use =
         t.NewNode(t.simplified()->ChangeTaggedToInt32(), other_load);
 
-    Node* add = t.NewNode(t.javascript()->Add(), value_use, other_use,
-                          param_context, other_load, start);
+    Node* add = t.NewNode(t.javascript()->Add(LanguageMode::SLOPPY), value_use,
+                          other_use, param_context, other_load, start);
 
     Node* ret = t.NewNode(t.common()->Return(), add, effect_use, start);
     Node* end = t.NewNode(t.common()->End(), ret);
     USE(end);
     t.graph()->SetEnd(end);
 
     // Double check the above graph is what we expect, or the test is broken.
     CheckEffectInput(effect_in, load);
     CheckEffectInput(load, effect_use);
 
@@ skipping 65 matching lines @@
   {
     FunctionTester T(
         "(function() { if (false) { var x = 1; } function inc(a)"
         " { return a + x; } return inc; })()");  // x is undefined!
 
     CHECK(T.Call(T.Val(0.0), T.Val(0.0)).ToHandleChecked()->IsNaN());
     CHECK(T.Call(T.Val(2.0), T.Val(0.0)).ToHandleChecked()->IsNaN());
     CHECK(T.Call(T.Val(-2.1), T.Val(0.0)).ToHandleChecked()->IsNaN());
   }
 }