Include type of missing trait methods in error

Provide either a span pointing to the original definition of missing
trait items, or a message with the inferred definitions.

src/test/ui/span/impl-wrong-item-for-trait.rs

@@ -0,0 +1,56 @@
+// Copyright 2015 The Rust Project Developers. See the COPYRIGHT
+// file at the top-level directory of this distribution and at
+// http://rust-lang.org/COPYRIGHT.
+//
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+
+#![feature(associated_consts)]
+
+use std::fmt::Debug;
+
+trait Foo {
+    fn bar(&self);
+    const MY_CONST: u32;
+}
+
+pub struct FooConstForMethod;
+
+impl Foo for FooConstForMethod {
+    //~^ ERROR E0046
+    //~| NOTE missing `bar` in implementation
+    const bar: u64 = 1;
+    //~^ ERROR E0323
+    //~| NOTE does not match trait
+    const MY_CONST: u32 = 1;
+}
+
+pub struct FooMethodForConst;
+
+impl Foo for FooMethodForConst {
+    //~^ ERROR E0046
+    //~| NOTE missing `MY_CONST` in implementation
+    fn bar(&self) {}
+    fn MY_CONST() {}
+    //~^ ERROR E0324
+    //~| NOTE does not match trait
+}
+
+pub struct FooTypeForMethod;
+
+impl Foo for FooTypeForMethod {
+    //~^ ERROR E0046
+    //~| NOTE missing `bar` in implementation
+    type bar = u64;
+    //~^ ERROR E0325
+    //~| NOTE does not match trait
+    const MY_CONST: u32 = 1;
+}
+
+impl Debug for FooTypeForMethod {
+}
+
+fn main () {}