[wasm] Do a proper HasProperty() check in the memory and table setup.

test/mjsunit/wasm/memory.js

Index: test/mjsunit/wasm/memory.js
diff --git a/test/mjsunit/wasm/memory.js b/test/mjsunit/wasm/memory.js
index a90d44c41ad8607c166d853ea69be316f7e7f8b4..e86825bd27c7000a88c047e5b392d1e9e386b377 100644
--- a/test/mjsunit/wasm/memory.js
+++ b/test/mjsunit/wasm/memory.js
@@ -8,6 +8,13 @@
 
 var outOfUint32RangeValue = 1e12;
 
+function assertMemoryIsValid(memory) {
+  assertSame(WebAssembly.Memory.prototype, memory.__proto__);
+  assertSame(WebAssembly.Memory, memory.constructor);
+  assertTrue(memory instanceof Object);
+  assertTrue(memory instanceof WebAssembly.Memory);
+}
+
 (function TestConstructor() {
   assertTrue(WebAssembly.Memory instanceof Function);
   assertSame(WebAssembly.Memory, WebAssembly.Memory.prototype.constructor);
@@ -28,18 +35,53 @@ var outOfUint32RangeValue = 1e12;
   assertThrows(() => new WebAssembly.Memory({initial: 10, maximum: 9}), RangeError);
 
   let memory = new WebAssembly.Memory({initial: 1});
-  assertSame(WebAssembly.Memory.prototype, memory.__proto__);
-  assertSame(WebAssembly.Memory, memory.constructor);
-  assertTrue(memory instanceof Object);
-  assertTrue(memory instanceof WebAssembly.Memory);
+  assertMemoryIsValid(memory);
 })();
 
 (function TestConstructorWithMaximum() {
   let memory = new WebAssembly.Memory({initial: 1, maximum: 10});
-  assertSame(WebAssembly.Memory.prototype, memory.__proto__);
-  assertSame(WebAssembly.Memory, memory.constructor);
-  assertTrue(memory instanceof Object);
-  assertTrue(memory instanceof WebAssembly.Memory);
+  assertMemoryIsValid(memory);
+})();
+
+(function TestInitialIsUndefined() {
+  // New memory with initial = undefined, which means initial = 0.
+  let memory = new WebAssembly.Memory({initial: undefined});
+  assertMemoryIsValid(memory);
+})();
+
+(function TestMaximumIsUndefined() {
+  // New memory with maximum = undefined, which means maximum = 0.
+  let memory = new WebAssembly.Memory({initial: 0, maximum: undefined});
+  assertMemoryIsValid(memory);
+})();
+
+(function TestMaximumIsReadOnce() {
+  var a = true;
+  var desc = {initial: 10};
+  Object.defineProperty(desc, 'maximum', {get: function() {
+    if (a) {
+      a = false;
+      return 16;
+    }
+    else {
+      // Change the return value on the second call so it throws.
+      return -1;
+    }
+  }});
+  let memory = new WebAssembly.Memory(desc);
+  assertMemoryIsValid(memory);
+})();
+
+(function TestMaximumDoesHasProperty() {
+  var hasPropertyWasCalled = false;
+  var desc = {initial: 10};
+  var proxy = new Proxy({maximum: 16}, {
+    has: function(target, name) { hasPropertyWasCalled = true; }
+  });
+  Object.setPrototypeOf(desc, proxy);
+  let memory = new WebAssembly.Memory(desc);
+  assertMemoryIsValid(memory);
+  assertTrue(hasPropertyWasCalled);
 })();
 
 (function TestBuffer() {