testcase added for rust-lang#3878

Author: vertexclique

src/test/run-pass/unused-move.rs

@@ -0,0 +1,9 @@
+// Issue #3878
+// Issue Name: Unused move causes a crash
+// Abstract: zero-fill to block after drop
+
+fn main()
+{
+    let y = ~1;
+    move y;
+}