Ignore libcore test that requires unwinding support

patches/0023-core-Ignore-failing-tests.patch

@@ -10,6 +10,26 @@ Subject: [PATCH] [core] Ignore failing tests
  src/libcore/tests/time.rs       |  1 +
  4 files changed, 18 insertions(+), 2 deletions(-)
 
+diff --git a/src/libcore/tests/array.rs b/src/libcore/tests/array.rs
+index 4bc44e9..8e3c7a4 100644
+--- a/src/libcore/tests/array.rs
++++ b/src/libcore/tests/array.rs
+@@ -242,6 +242,7 @@ fn iterator_drops() {
+     assert_eq!(i.get(), 5);
+ }
+ 
++/*
+ // This test does not work on targets without panic=unwind support.
+ // To work around this problem, test is marked is should_panic, so it will
+ // be automagically skipped on unsuitable targets, such as
+@@ -283,6 +284,7 @@ fn array_default_impl_avoids_leaks_on_panic() {
+     assert_eq!(COUNTER.load(Relaxed), 0);
+     panic!("test succeeded")
+ }
++*/
+ 
+ #[test]
+ fn empty_array_is_always_default() {
 diff --git a/src/libcore/tests/iter.rs b/src/libcore/tests/iter.rs
 index c9096b7..be37fcd 100644
 --- a/src/libcore/tests/iter.rs