Add tests for unsafe::reinterpret_cast

Author: brson

src/test/stdtest/stdtest.rc

@@ -34,6 +34,7 @@ mod task;
 mod test;
 mod treemap;
 mod uint;
+mod unsafe;
 mod vec;
 
 // Local Variables:

src/test/stdtest/unsafe.rs

@@ -0,0 +1,13 @@
+import std::unsafe;
+
+#[test]
+fn reinterpret_cast() unsafe {
+    assert unsafe::reinterpret_cast(1) == 1u;
+}
+
+#[test]
+#[should_fail]
+#[ignore(cfg(target_os = "win32"))]
+fn reinterpret_cast_wrong_size() unsafe {
+    let _i: uint = unsafe::reinterpret_cast(0u8);
+}