patch 9.0.0270: some values of 'path' and 'tags' invalid in the tiny version

Problem:    Some values of 'path' and 'tags' do not work in the tiny version.
Solution:   Graduate the +path_extra feature.
diff --git a/src/feature.h b/src/feature.h
index 9c094e5..bffd80a 100644
--- a/src/feature.h
+++ b/src/feature.h
@@ -117,6 +117,7 @@
  * +smartindent		smart C code indenting when the 'si' option is set.
  * +textobjects		Text objects: "vaw", "das", etc.
  * +file_in_path	"gf" and "<cfile>" commands.
+ * +path_extra		up/downwards searching in 'path' and 'tags'.
  *
  * Obsolete:
  * +tag_old_static	Old style static tags: "file:tag  file  ..".
@@ -211,13 +212,6 @@
 #endif
 
 /*
- * +path_extra		up/downwards searching in 'path' and 'tags'.
- */
-#ifdef FEAT_NORMAL
-# define FEAT_PATH_EXTRA
-#endif
-
-/*
  * +rightleft		Right-to-left editing/typing support.
  */
 #if defined(FEAT_BIG) && !defined(DISABLE_RIGHTLEFT)