[wasm] Fix asm.js semantics for divide by zero in WASM translation.

test/mjsunit/wasm/asm-wasm-u32.js

 // Copyright 2016 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: --expose-wasm
 
 function WrapInAsmModule(func) {
   function MODULE_NAME(stdlib) {
     "use asm";
     var imul = stdlib.Math.imul;
@@ skipping 25 matching lines @@
   print("Testing " + asmfunc.name + " (wasm)...");
   var wasm_module = Wasm.instantiateModuleFromAsm(asm_source, stdlib);
   expect(wasm_module);
 }
 
 const imul = Math.imul;
 
 function u32_add(a, b) {
   a = a | 0;
   b = b | 0;
-  return +((a >>> 0) + (b >>> 0));
+  return +(((a >>> 0) + (b >>> 0)) >>> 0);
 }
 
 function u32_sub(a, b) {
   a = a | 0;
   b = b | 0;
-  return +((a >>> 0) - (b >>> 0));
+  return +(((a >>> 0) - (b >>> 0)) >>> 0);
 }
 
 function u32_mul(a, b) {
   a = a | 0;
   b = b | 0;
   return +imul(a >>> 0, b >>> 0);
 }
 
 function u32_div(a, b) {
   a = a | 0;
   b = b | 0;
-  return ((a >>> 0) / (b >>> 0)) | 0;
+  return +(((a >>> 0) / (b >>> 0)) >>> 0);
 }
 
 function u32_mod(a, b) {
   a = a | 0;
   b = b | 0;
-  return ((a >>> 0) % (b >>> 0)) | 0;
+  return +(((a >>> 0) % (b >>> 0)) >>> 0);
 }
 
 function u32_and(a, b) {
   a = a | 0;
   b = b | 0;
   return +((a >>> 0) & (b >>> 0));
 }
 
 function u32_or(a, b) {
   a = a | 0;
@@ skipping 100 matching lines @@
   -10, -20, -30, -31, -32, -33, -100, -2000,
   -30000, -400000, -5000000,
   -100000000, -2000000000,
   -2147483646,
   -2147483647,
   -2147483648,
   -2147483649,
 ];
 
 var funcs = [
-// TODO(bradnelson):  u32_add,
-// TODO(bradnelson): u32_sub,
-// TODO(titzer): u32_mul requires Math.imul
-// TODO(titzer): u32_div by zero is incorrect
-// TODO(titzer): u32_mod by zero is incorrect
+  u32_add,
+  u32_sub,
+  u32_div,
+  u32_mod,
 // TODO(titzer): u32_mul crashes turbofan in asm.js mode
   u32_and,
   u32_or,
   u32_xor,
 // TODO(titzer): u32_shl on arm
 // TODO(titzer): u32_shr on arm
 // TODO(titzer): u32_sar on arm
   u32_eq,
   u32_ne,
   u32_lt,
@@ skipping 11 matching lines @@
       for (a of inputs) {
         for (b of inputs) {
           var expected = func(a, b);
           assertEquals(expected, module.main(a, b));
         }
       }
     });
   }
 
 })();