[Bug libobjc/63765] [5.0 Regression] libobjc testsuite failures on AIX caused by setting _XOPEN_SOURCE

[dje at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=63765

--- Comment #17 from David Edelsohn <dje at gcc dot gnu.org> ---
What other comments are needed to install the alternative patch?  It works for
Solaris and AIX, where the problems started.