[wasm] Forbid sign mismatch in asm typer.

src/typing-asm.cc

 // 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.
 
 #include "src/typing-asm.h"
 
 #include <limits>
 
 #include "src/v8.h"
 
@@ skipping 1281 matching lines @@
           intish_ = left_intish + right_intish + 1;
           if (expr->op() == Token::ADD || expr->op() == Token::SUB) {
             if (intish_ > kMaxUncombinedAdditiveSteps) {
               FAIL(expr, "too many consecutive additive ops");
             }
           } else {
             if (intish_ > kMaxUncombinedMultiplicativeSteps) {
               FAIL(expr, "too many consecutive multiplicative ops");
             }
           }
+          if (expr->op() == Token::MOD || expr->op() == Token::DIV) {
+            if (!((left_type->Is(cache_.kAsmSigned) &&
+                   right_type->Is(cache_.kAsmSigned)) ||
+                  (left_type->Is(cache_.kAsmUnsigned) &&
+                   right_type->Is(cache_.kAsmUnsigned)))) {
+              FAIL(expr,
+                   "left and right side of integer / or % "
+                   "must match and be signed or unsigned");
+            }
+          }
           RECURSE(IntersectResult(expr, cache_.kAsmInt));
           return;
         }
       } else if (expr->op() == Token::MUL && expr->right()->IsLiteral() &&
                  right_type->Is(cache_.kAsmDouble) &&
                  expr->right()->AsLiteral()->raw_value()->ContainsDot() &&
                  expr->right()->AsLiteral()->raw_value()->AsNumber() == 1.0) {
         // For unary +, expressed as x * 1.0
         if (expr->left()->IsCall() &&
             Type::Number()->Is(bounds_.get(expr->left()).upper)) {
@@ skipping 325 matching lines @@
 }
 
 
 void AsmTyper::VisitRewritableExpression(RewritableExpression* expr) {
   RECURSE(Visit(expr->expression()));
 }
 
 
 }  // namespace internal
 }  // namespace v8