rusti: disable tests on 32bit mac. r=burningtree.

src/librusti/rusti.rc

@@ -537,6 +537,9 @@ mod tests {
     }
 
     #[test]
+    // FIXME: #7220 rusti on 32bit mac doesn't work.
+    #[cfg(not(and(target_word_size=32,
+                  target_os="mac")))]
     fn run_all() {
         // FIXME(#7071):
         // By default, unit tests are run in parallel. Rusti, on the other hand,
@@ -648,6 +651,9 @@ mod tests {
     }
 
     #[test]
+    // FIXME: #7220 rusti on 32bit mac doesn't work.
+    #[cfg(not(and(target_word_size=32,
+                  target_os="mac")))]
     fn exit_quits() {
         let mut r = repl();
         assert!(r.running);