intel: Instance functions create and destroy objects

Also they do the same init and removal as existing InitAndEnumerateGpus.
diff --git a/include/xglDbg.h b/include/xglDbg.h
index b040710..dfed1a8 100644
--- a/include/xglDbg.h
+++ b/include/xglDbg.h
@@ -87,6 +87,7 @@
     XGL_DBG_OBJECT_FRAMEBUFFER            = 0x1d,
     XGL_DBG_OBJECT_RENDER_PASS            = 0x1e,
 
+    XGL_DBG_OBJECT_INSTANCE,
     XGL_DBG_OBJECT_BUFFER,
     XGL_DBG_OBJECT_BUFFER_VIEW,
     XGL_DBG_OBJECT_DESCRIPTOR_SET_LAYOUT,