Add methods for creating V8 extras-based ReadableStreams from C++

Source/core/streams/CountQueuingStrategy.js

+(function(global, exports) {
+    'use strict';
+
+    const NONE = 0;
+    const DONT_ENUM = 2;
+
+    class CountQueuingStrategy {
+        constructor(options) {
+            %AddNamedProperty(this, 'highWaterMark', options.highWaterMark, NONE);
+        }
+
+        size(chunk) {
+            return 1;
+        }
+    }
+
+    %AddNamedProperty(global, 'CountQueuingStrategy', CountQueuingStrategy, DONT_ENUM);
+
+    // Export a separate copy that doesn't need options objects and can't be interfered with.
+    exports.BuiltInCountQueuingStrategy = class BuiltInCountQueuingStrategy {
+        constructor(highWaterMark) {
+            %AddNamedProperty(this, 'highWaterMark', highWaterMark, NONE);
+        }
+
+        size(chunk) {
+            return 1;
+        }
+    };
+});