remove ctor from ast (take 2) (no review: just dead code removal)

src/test/compile-fail/cap-clause-use-after-move.rs

@@ -1,7 +1,5 @@
-// error-pattern:Unsatisfied precondition constraint
-
 fn main() {
     let x = 5;
-    let _y = fn~(move x) { };
-    let _z = x; //< error: Unsatisfied precondition constraint
+    let _y = fn~(move x) { }; //~ WARNING captured variable `x` not used in closure
+    let _z = x; //~ ERROR use of moved variable: `x`
 }

src/test/compile-fail/issue-2590.rs

@@ -10,7 +10,7 @@ trait parse {
 
 impl parser: parse {
     fn parse() -> ~[int] {
-        dvec::unwrap(move self.tokens) //~ ERROR illegal move from self
+        dvec::unwrap(move self.tokens) //~ ERROR moving out of immutable field
     }
 }
 

src/test/compile-fail/regions-glb-free-free.rs

@@ -19,7 +19,7 @@ mod argparse {
         fn set_desc(self, s: &str) -> Flag {
             Flag { //~ ERROR cannot infer an appropriate lifetime
                 name: self.name,
-                desc: s,
+                desc: s, //~ ERROR cannot infer an appropriate lifetime
                 max_count: self.max_count,
                 value: self.value
             }