[Atomics] Fix atomic access index validation

test/mjsunit/asm/atomics-load.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: --harmony-sharedarraybuffer
 
 function Module(stdlib, foreign, heap, offset) {
   "use asm";
   var MEM8 = new stdlib.Int8Array(heap, offset);
   var MEM16 = new stdlib.Int16Array(heap, offset);
@@ skipping 44 matching lines @@
   };
 }
 
 function clearArray() {
   var ui8 = new Uint8Array(sab);
   for (var i = 0; i < sab.byteLength; ++i) {
     ui8[i] = 0;
   }
 }
 
-function testElementType(taConstr, f, oobValue, offset) {
+function testElementType(taConstr, f, offset) {
   clearArray();
 
   var ta = new taConstr(sab, offset);
   var name = Object.prototype.toString.call(ta);
   ta[0] = 10;
   assertEquals(10, f(0), name);
   assertEquals(0, f(1), name);
   // out of bounds
-  assertEquals(oobValue, f(-1), name);
-  assertEquals(oobValue, f(ta.length), name);
+  assertThrows(function() { f(-1); });
+  assertThrows(function() { f(ta.length); });
 }
 
 function testElement(m, offset) {
-  testElementType(Int8Array, m.loadi8, 0, offset);
-  testElementType(Int16Array, m.loadi16, 0, offset);
-  testElementType(Int32Array, m.loadi32, 0, offset);
-  testElementType(Uint8Array, m.loadu8, 0, offset);
-  testElementType(Uint16Array, m.loadu16, 0, offset);
-  testElementType(Uint32Array, m.loadu32, 0, offset);
+  testElementType(Int8Array, m.loadi8, offset);
+  testElementType(Int16Array, m.loadi16, offset);
+  testElementType(Int32Array, m.loadi32, offset);
+  testElementType(Uint8Array, m.loadu8, offset);
+  testElementType(Uint16Array, m.loadu16, offset);
+  testElementType(Uint32Array, m.loadu32, offset);
 }
 
 var offset = 0;
 var sab = new SharedArrayBuffer(16);
 var m1 = Module(this, {}, sab, offset);
 testElement(m1, offset);
 
 offset = 32;
 sab = new SharedArrayBuffer(64);
 var m2 = Module(this, {}, sab, offset);
 testElement(m2, offset);