Fix bug in llvm type signature of function items; enable three more tests.

src/Makefile

@@ -517,6 +517,9 @@ TEST_XFAILS_LLVM := $(TASK_XFAILS) \
 
 TEST_XFAILS_SELF := $(filter-out \
                       $(addprefix test/run-pass/, \
+                        bool-not.rs \
+                        dead-code-one-arm-if.rs \
+                        hello.rs \
                         int.rs \
                         item-name-overload.rs \
                         multiline-comment.rs \

src/comp/middle/trans.rs

@@ -280,7 +280,7 @@ fn type_of_inner(@trans_ctxt cx, @typeck.ty t) -> TypeRef {
             ret T_struct(tys);
         }
         case (typeck.ty_fn(?args, ?out)) {
-            let vec[TypeRef] atys = vec();
+            let vec[TypeRef] atys = vec(T_taskptr());
             for (typeck.arg arg in args) {
                 let TypeRef t = type_of(cx, arg.ty);
                 alt (arg.mode) {