[wasm] Fix bounds check for zero initial memory.

test/mjsunit/wasm/import-memory.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
 
 load("test/mjsunit/wasm/wasm-constants.js");
 load("test/mjsunit/wasm/wasm-module-builder.js");
 
 (function TestOne() {
@@ skipping 62 matching lines @@
 
   for (var i = 0; i < 1e11; i = i * 3 + 5) {
     for (var j = 0; j < 10; j++) {
       var val = i + 99077 + j;
       i32[j] = val;
       assertEquals(val | 0, i1.exports.foo(j * 4));
       assertEquals(val | 0, i2.exports.bar(j * 4));
     }
   }
 })();
+
+(function ValidateBoundsCheck() {
+  print("Validate bounds check");
+  let memory = new WebAssembly.Memory({initial: 1, maximum: 5});
+  assertEquals(kPageSize, memory.buffer.byteLength);
+  let i32 = new Int32Array(memory.buffer);
+  let builder = new WasmModuleBuilder();
+  // builder.addImportedMemory("mine");
+  builder.addImportedMemory("mine");
+  builder.addFunction("load", kSig_i_i)
+      .addBody([kExprGetLocal, 0, kExprI32LoadMem, 0, 0])
+      .exportFunc();
+  builder.addFunction("store", kSig_i_ii)
+      .addBody([kExprGetLocal, 0, kExprGetLocal, 1, kExprI32StoreMem, 0, 0,
+                kExprGetLocal, 1])
+      .exportFunc();
+  var offset;
+  let instance = builder.instantiate({mine: memory});
+  function load() { return instance.exports.load(offset); }
+  function store(value) { return instance.exports.store(offset, value); }
+
+  for (offset = 0; offset < kPageSize -3; offset+=4) {
+    store(offset);
+  }
+  for (offset = 0; offset < kPageSize - 3; offset+=4) {
+    assertEquals(offset, load());
+  }
+  for (offset = kPageSize - 3; offset < kPageSize + 4; offset++) {
+    assertTraps(kTrapMemOutOfBounds, load);
+  }
+})();