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, 4 insertions, 0 deletions

diff --git a/internal/symbol.h b/internal/symbol.h
index 0317f66561..8de6903ae2 100644
--- a/internal/symbol.h
+++ b/internal/symbol.h
@@ -13,6 +13,10 @@
 #include "ruby/encoding.h"      /* for rb_encoding */
 #include "internal/compilers.h" /* for __has_builtin */
 
+#ifdef rb_sym_intern_ascii_cstr
+# undef rb_sym_intern_ascii_cstr
+#endif
+
 /* symbol.c */
 VALUE rb_to_symbol_type(VALUE obj);
 VALUE rb_sym_intern(const char *ptr, long len, rb_encoding *enc);