Preparing libRS for for compilation on host.

Change-Id: I851add79831331c8a8b20dcccdb0817f8ad0c359
diff --git a/RenderScriptDefines.h b/RenderScriptDefines.h
index 308437d..ee9645c 100644
--- a/RenderScriptDefines.h
+++ b/RenderScriptDefines.h
@@ -50,6 +50,8 @@
 typedef void * RsProgramStore;
 typedef void * RsProgramRaster;
 
+typedef void * RsNativeWindow;
+
 typedef void (* RsBitmapCallback_t)(void *);
 
 typedef struct {