enable AppInit for non-wow64 on win8+

From bruen...@google.com on August 21, 2014 11:05:01

issue #1035 (closed) covers enabling AppInit for WOW64 on win8+. We blanket-disabled AppInit for win8+ but we should be able to enable for non-WOW64. This issue covers that.

Original issue: http://code.google.com/p/dynamorio/issues/detail?id=1522