test: update flag to disable SharedArrayBuffer

`--no-harmony-sharedarraybuffer` was removed from V8 but it's still
possible to disable the feature with `--enable-sharedarraybuffer-per-context`.

Author: targos

lib/internal/worker.js

@@ -99,7 +99,7 @@ let cwdCounter;
 
 const environmentData = new SafeMap();
 
-// SharedArrayBuffers can be disabled with --no-harmony-sharedarraybuffer.
+// SharedArrayBuffers can be disabled with --enable-sharedarraybuffer-per-context.
 if (isMainThread && SharedArrayBuffer !== undefined) {
   cwdCounter = new Uint32Array(new SharedArrayBuffer(4));
   const originalChdir = process.chdir;

test/parallel/test-worker-no-sab.js

@@ -1,4 +1,4 @@
-// Flags: --no-harmony-sharedarraybuffer
+// Flags: --enable-sharedarraybuffer-per-context
 
 'use strict';