marshal.c: new functions for extensions

* marshal.c (rb_marshal_dump_limited): new function for extension
  libraries to dump object with limited nest level.

* marshal.c (rb_marshal_load_with_proc): new function for extension
  libraries to load object with hook proc.

include/ruby/intern.h

@@ -598,6 +598,8 @@ void rb_fd_fix_cloexec(int fd);
 /* marshal.c */
 VALUE rb_marshal_dump(VALUE, VALUE);
 VALUE rb_marshal_load(VALUE);
+VALUE rb_marshal_dump_limited(VALUE obj, VALUE port, int level);
+VALUE rb_marshal_load_with_proc(VALUE port, VALUE proc);
 void rb_marshal_define_compat(VALUE newclass, VALUE oldclass, VALUE (*dumper)(VALUE), VALUE (*loader)(VALUE, VALUE));
 /* numeric.c */
 NORETURN(void rb_num_zerodiv(void));

marshal.c

@@ -106,8 +106,6 @@ typedef struct {
 
 static st_table *compat_allocator_tbl;
 static VALUE compat_allocator_tbl_wrapper;
-static VALUE rb_marshal_dump_limited(VALUE obj, VALUE port, int limit);
-static VALUE rb_marshal_load_with_proc(VALUE port, VALUE proc);
 
 static int
 mark_marshal_compat_i(st_data_t key, st_data_t value)