[Bug?] SIG2STR_MAX not good for #if

[Mingye Wang]

On Mon, Jun 19, 2023 at 7:12 PM Joel Sherrill <joel@rtems.org> wrote:
>
> FWIW This appears to be a common extension and ere does not appear in the POSIX standard.
>
> Given that, it should be compatible with glibc

It's part of the proposed standard per link [1] of original message.
It's already been put into the branch for the next issue per its last
comment.