Bug 1534522 - Allow to specify different task ids for artifacts. r=dm…

…ajor

Bug 1528123 added a way to specify a task id to influence mach
artifact. In the case of upcoming EME-enabled win64-aarch64 builds, we
need to be able to specify two different task ids, which a single
environment variable doesn't really allow.

So extend the scheme to check environment variables with the build
type included in the variable name.

Differential Revision: https://phabricator.services.mozilla.com/D23101

--HG--
extra : moz-landing-system : lando

python/mozbuild/mozbuild/artifacts.py

@@ -1271,8 +1271,12 @@ def install_from(self, source, distdir):
             if source:
                 return self.install_from_revset(source, distdir)
 
-            if 'MOZ_ARTIFACT_TASK' in os.environ:
-                return self.install_from_task(os.environ['MOZ_ARTIFACT_TASK'], distdir)
+            for var in (
+                'MOZ_ARTIFACT_TASK_%s' % self._job.upper().replace('-', '_'),
+                'MOZ_ARTIFACT_TASK',
+            ):
+                if var in os.environ:
+                    return self.install_from_task(os.environ[var], distdir)
 
             return self.install_from_recent(distdir)