decouple internal.h headers

Saves comitters' daily life by avoid #include-ing everything from
internal.h to make each file do so instead.  This would significantly
speed up incremental builds.

We take the following inclusion order in this changeset:

1.  "ruby/config.h", where _GNU_SOURCE is defined (must be the very
    first thing among everything).
2.  RUBY_EXTCONF_H if any.
3.  Standard C headers, sorted alphabetically.
4.  Other system headers, maybe guarded by #ifdef
5.  Everything else, sorted alphabetically.

Exceptions are those win32-related headers, which tend not be self-
containing (headers have inclusion order dependencies).

1 files changed, 1 insertions, 0 deletions

diff --git a/symbol.h b/symbol.h
index 4b5c676d55..45cf1b21c9 100644
--- a/symbol.h
+++ b/symbol.h
@@ -13,6 +13,7 @@
 #define RUBY_SYMBOL_H 1
 
 #include "id.h"
+#include "ruby/encoding.h"
 
 #define DYNAMIC_ID_P(id) (!(id&ID_STATIC_SYM)&&id>tLAST_OP_ID)
 #define STATIC_ID2SYM(id)  (((VALUE)(id)<<RUBY_SPECIAL_SHIFT)|SYMBOL_FLAG)