Bug 1536250 - disable test_dmd.js r=jmaher

Disable this test which intermittently fails in xpcshell.

Differential Revision: https://phabricator.services.mozilla.com/D23956

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

memory/replace/dmd/test/xpcshell.ini

@@ -31,4 +31,4 @@ support-files =
 
 [test_dmd.js]
 dmd = true
-skip-if = !(os=='linux' || os=='mac' || (os=='win' && !pgo))
+skip-if = !(os=='linux' || os=='mac' || (os=='win' && !pgo)) || (os == "win" && processor == "aarch64") # aarch64 due to 1536250