[foozzie] Improve mocks for typed arrays

This wraps float arrays with a proxy to make raw buffer use slow paths avoiding different NAN patterns.

This also mocks out large typed arrays when passing the lenth as third constructor parameter.

BUG=chromium:691287,chromium:690898
NOTRY=true

Change-Id: Ic4295b0d8690e5209aceeda9ed93efdd580194c0
Reviewed-on: https://chromium-review.googlesource.com/441624
Commit-Queue: Michael Achenbach <machenbach@chromium.org>
Reviewed-by: Yang Guo <yangguo@chromium.org>
Cr-Commit-Position: refs/heads/master@{#43229}

tools/foozzie/v8_mock.js

@@ -70,8 +70,8 @@ Object.defineProperty(
   var mock = function(arrayType) {
     var handler = {
       construct: function(target, args) {
-        return new (
-            Function.prototype.bind.apply(arrayType, [null].concat(args)));
+        return new Proxy(
+            Function.prototype.bind.apply(arrayType, [null].concat(args)), {});
       },
     };
     return new Proxy(arrayType, handler);

tools/foozzie/v8_mock_archs.js

@@ -20,6 +20,10 @@
             Number.isInteger(args[0]) &&
             args[0] > 1048576) {
           args[0] = 1048576
+        } else if (args.length > 2 &&
+                   Number.isInteger(args[2]) &&
+                   args[2] > 1048576) {
+          args[2] = 1048576
         }
         return new (
             Function.prototype.bind.apply(arrayType, [null].concat(args)));