[strong] Disallow implicit conversions for binary arithmetic operations

src/ic/ic.cc

Index: src/ic/ic.cc
diff --git a/src/ic/ic.cc b/src/ic/ic.cc
index a6ae92a892c06ac9dcc88ecf093a0201e9f0eb12..7a42d23f0c748c6095bb16721c4e9b6cff50b250 100644
--- a/src/ic/ic.cc
+++ b/src/ic/ic.cc
@@ -2568,7 +2568,7 @@ MaybeHandle<Object> BinaryOpIC::Transition(
 
   // Compute the actual result using the builtin for the binary operation.
   Object* builtin = isolate()->js_builtins_object()->javascript_builtin(
-      TokenToJSBuiltin(state.op()));
+      TokenToJSBuiltin(state.op(), state.language_mode()));
   Handle<JSFunction> function = handle(JSFunction::cast(builtin), isolate());
   Handle<Object> result;
   ASSIGN_RETURN_ON_EXCEPTION(
@@ -2805,43 +2805,62 @@ RUNTIME_FUNCTION(Unreachable) {
 }
 
 
-Builtins::JavaScript BinaryOpIC::TokenToJSBuiltin(Token::Value op) {
-  switch (op) {
-    default:
-      UNREACHABLE();
-    case Token::ADD:
-      return Builtins::ADD;
-      break;
-    case Token::SUB:
-      return Builtins::SUB;
-      break;
-    case Token::MUL:
-      return Builtins::MUL;
-      break;
-    case Token::DIV:
-      return Builtins::DIV;
-      break;
-    case Token::MOD:
-      return Builtins::MOD;
-      break;
-    case Token::BIT_OR:
-      return Builtins::BIT_OR;
-      break;
-    case Token::BIT_AND:
-      return Builtins::BIT_AND;
-      break;
-    case Token::BIT_XOR:
-      return Builtins::BIT_XOR;
-      break;
-    case Token::SAR:
-      return Builtins::SAR;
-      break;
-    case Token::SHR:
-      return Builtins::SHR;
-      break;
-    case Token::SHL:
-      return Builtins::SHL;
-      break;
+Builtins::JavaScript BinaryOpIC::TokenToJSBuiltin(Token::Value op,
+                                                  LanguageMode language_mode) {
+  if (is_strong(language_mode)) {
+    switch (op) {
+      default:
+        UNREACHABLE();
+      case Token::ADD:
+        return Builtins::ADD;
+      case Token::SUB:
+        return Builtins::SUB_STRONG;
+      case Token::MUL:
+        return Builtins::MUL_STRONG;
+      case Token::DIV:
+        return Builtins::DIV_STRONG;
+      case Token::MOD:
+        return Builtins::MOD_STRONG;
+      case Token::BIT_OR:
+        return Builtins::BIT_OR;
+      case Token::BIT_AND:
+        return Builtins::BIT_AND;
+      case Token::BIT_XOR:
+        return Builtins::BIT_XOR;
+      case Token::SAR:
+        return Builtins::SAR;
+      case Token::SHR:
+        return Builtins::SHR;
+      case Token::SHL:
+        return Builtins::SHL;
+    }
+  } else {
+    switch (op) {
+      default:
+        UNREACHABLE();
+      case Token::ADD:
+        return Builtins::ADD;
+      case Token::SUB:
+        return Builtins::SUB;
+      case Token::MUL:
+        return Builtins::MUL;
+      case Token::DIV:
+        return Builtins::DIV;
+      case Token::MOD:
+        return Builtins::MOD;
+      case Token::BIT_OR:
+        return Builtins::BIT_OR;
+      case Token::BIT_AND:
+        return Builtins::BIT_AND;
+      case Token::BIT_XOR:
+        return Builtins::BIT_XOR;
+      case Token::SAR:
+        return Builtins::SAR;
+      case Token::SHR:
+        return Builtins::SHR;
+      case Token::SHL:
+        return Builtins::SHL;
+    }
   }
 }