spkg-configure.m4 for libatomic

[dimpase]

this might need a tricky (?) check that the configuration is as needed for ecl.

otherwise, libatomic has no deps, and gc only depends on libatomic

CC: @embray @orlitzky

Component: build: configure

Author: Michael Orlitzky

Branch/Commit: e86ec71

Reviewer: Isuru Fernando

Issue created by migration from https://trac.sagemath.org/ticket/28045

[embray]

comment:1

Ticket retargeted after milestone closed

[orlitzky]

Branch: u/mjo/ticket/28045

[orlitzky]

comment:2

Should we do these separately? If gc winds up being tricky, we can do the dead-simple libatomic in the meantime.

[orlitzky]

Commit: e86ec71

[orlitzky]

comment:3

Let's do libatomic here, and gc in #28991. I'd like to get the easy ones out of the way and then we can spent as much time as it takes to do the tricky ones.

[isuruf]

Reviewer: Isuru Fernando