[Bug other/67627] libatomic parallel build failure

[nsz at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=67627

--- Comment #1 from nsz at gcc dot gnu.org ---
adding

all-multi: $(libatomic_la_LIBADD)

to libatomic/Makefile.in solves the problem for me,
but i'm not sure what's the automake way of doing
this