Drop MJIT_FUNC_EXPORTED from rb_hash_bulk_insert

it's official API after r67677

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@67690 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

hash.c

@@ -4412,7 +4412,7 @@ ar_bulk_insert(VALUE hash, long argc, const VALUE *argv)
     }
 }
 
-MJIT_FUNC_EXPORTED void
+void
 rb_hash_bulk_insert(long argc, const VALUE *argv, VALUE hash)
 {
     HASH_ASSERT(argc % 2 == 0);