Error while building the devel branch: relocatable.c:31: error: expected identifier or '(' at end of input

[Yuri Kanivetsky]

The details are in a gist:
https://gist.github.com/x-yuri/0246bb560b0741751c0d6f6749164d36

It builds successfully after removing the `#include <stdlib.h>` line
in lib/intl/relocatable.h (see the sed line in a.sh):

https://git.savannah.gnu.org/cgit/bash.git/tree/lib/intl/relocatable.h?id=50ffbc9ddc29a52e37efd8ed5c72dbe407257cc7#n21

stdlib.h in this case comes from fortify-headers, which wraps
(#include_next <stdlib.h>) stdlib.h supposedly from musl-dev:

http://git.2f30.org/fortify-headers/file/include/stdlib.h.html#l23

The issue appears in
https://git.savannah.gnu.org/cgit/bash.git/commit/?id=50ffbc9ddc29a52e37efd8ed5c72dbe407257cc7

Can you explain what exactly is happening here? Is it an issue with
bash, fortify-headers or anything else? Judging from the `gcc -E`
output it looks like preprocessed relocatable.c ends with
__extension__, which is... an error? Is it because `#include_next
<stdlib.h>` produces no output? Why?

Regards,
Yuri