Testcase (XFAILed) for mutable alias vec weirdness.

src/Makefile

@@ -321,6 +321,7 @@ TEST_XFAILS_X86 :=  test/run-pass/mlist-cycle.rs \
                     test/run-pass/vec-slice.rs \
                     test/run-pass/generic-fn-infer.rs \
                     test/run-pass/generic-recursive-tag.rs \
+                    test/run-pass/mutable-alias-vec.rs \
                     test/run-pass/mutable-vec-drop.rs \
                     test/run-pass/bind-obj-ctor.rs \
                     test/run-pass/task-comm.rs \
@@ -384,6 +385,7 @@ TEST_XFAILS_LLVM := $(addprefix test/run-pass/, \
                       many.rs \
                       mlist-cycle.rs \
                       mlist.rs \
+                      mutable-alias-vec.rs \
                       mutable-vec-drop.rs \
                       mutual-recursion-group.rs \
                       native-mod.rc \

src/test/run-pass/mutable-alias-vec.rs

@@ -0,0 +1,7 @@
+// -*- rust -*-
+
+fn grow(mutable &vec[int] v) {
+  v += vec(1);
+}
+
+fn main() {}