test: add tests for SharedArrayBuffer

refer issue #8440

Author: ojss

test/parallel/test-buffer-sharedarraybuffer.js

@@ -0,0 +1,25 @@
+/*global SharedArrayBuffer*/
+'use strict';
+// Flags: --harmony-sharedarraybuffer
+
+require('../common');
+const assert = require('assert');
+const Buffer = require('buffer').Buffer;
+
+const sab = new SharedArrayBuffer(24);
+const arr = new Uint16Array(sab);
+const ar = new Uint16Array(12);
+ar[0] = 5000;
+arr[0] = 5000;
+arr[1] = 4000;
+ar[1] = 4000;
+
+var arr_buf = Buffer.from(arr.buffer);
+var ar_buf = Buffer.from(ar.buffer);
+
+assert.deepStrictEqual(arr_buf, ar_buf, 0);
+
+arr[1] = 6000;
+ar[1] = 6000;
+
+assert.deepStrictEqual(arr_buf, ar_buf, 0);