ruby.h: use __extension__

* include/ruby/ruby.h (ruby_fl_type): use __extension__ to get rid
  of pedantic warning against RUBY_FL_USER19.
  https://github.com/skylightio/skylight-ruby/issues/64
* include/ruby/ruby.h (rb_mul_size_overflow): ditto for use of
  int128.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@55764 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

ChangeLog

@@ -1,3 +1,12 @@
+Thu Jul 28 15:05:12 2016  Nobuyoshi Nakada  <nobu@ruby-lang.org>
+
+	* include/ruby/ruby.h (ruby_fl_type): use __extension__ to get rid
+	  of pedantic warning against RUBY_FL_USER19.
+	  https://github.com/skylightio/skylight-ruby/issues/64
+
+	* include/ruby/ruby.h (rb_mul_size_overflow): ditto for use of
+	  int128.
+
 Wed Jul 27 10:32:59 2016  Martin Duerst  <duerst@it.aoyama.ac.jp>
 
 	* enc/windows_1253.c: Remove dead code found by Coverity Scan.

include/ruby/ruby.h

@@ -792,6 +792,9 @@ VALUE rb_obj_setup(VALUE obj, VALUE klass, VALUE type);
 #define RGENGC_WB_PROTECTED_NODE_CREF 1
 #endif
 
+#ifdef __GNUC__
+__extension__
+#endif
 enum ruby_fl_type {
     RUBY_FL_WB_PROTECTED = (1<<5),
     RUBY_FL_PROMOTED0 = (1<<5),
@@ -1603,6 +1606,9 @@ static inline int
 rb_mul_size_overflow(size_t a, size_t b, size_t max, size_t *c)
 {
 #ifdef DSIZE_T
+# ifdef __GNUC__
+    __extension__
+# endif
     DSIZE_T c2 = (DSIZE_T)a * (DSIZE_T)b;
     if (c2 > max) return 1;
     *c = (size_t)c2;