Rename hb-*private.hh to hb-*.hh

Sorry for the noise, downstream custom builders.  Please adjust.

src/hb-aat-layout-feat-table.hh

diff --git a/src/hb-aat-layout-feat-table.hh b/src/hb-aat-layout-feat-table.hh
index 3e070d7..b700763 100644
--- a/src/hb-aat-layout-feat-table.hh
+++ b/src/hb-aat-layout-feat-table.hh
@@ -25,7 +25,7 @@
 #ifndef HB_AAT_LAYOUT_FEAT_TABLE_HH
 #define HB_AAT_LAYOUT_FEAT_TABLE_HH
 
-#include "hb-aat-layout-common-private.hh"
+#include "hb-aat-layout-common.hh"
 
 /*
  * feat -- Feature Name