Test: skip manual_ownership.swift on simulators / devices

The diagnostic messages are not yet stabilized, so we're
getting a differently-worded message for the same
fundamental issue, depending on the targeted platform.

rdar://164852821

Author: kavon

test/SIL/manual_ownership.swift

@@ -4,6 +4,18 @@
 
 // REQUIRES: swift_feature_ManualOwnership
 
+// FIXME(rdar://164852821): Some of the diagnostic message tailoring for assignments
+// are unstable when targeting platforms like the simulator, since we seem to emit
+// slightly different SIL which then throws off the heuristics. For example,
+//
+// <snip>/swift/test/SIL/manual_ownership.swift:431:68: error: incorrect message found
+//           self.baseCollection = baseCollection
+//           // expected-warning@-1 {{accessing 'baseCollection' may produce a copy}}
+//                                    ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+//            closure capture of 'baseCollection' requires independent copy of it; write [baseCollection = copy baseCollection] in the closure's capture list to acknowledge
+//
+// UNSUPPORTED: remote_run || device_run
+
 // MARK: types
 
 public class Whatever {