Update compiler error 0034 to use new format.

src/librustc_typeck/check/method/suggest.rs

@@ -242,6 +242,7 @@ macro_rules! report_function {
             MethodError::Ambiguity(sources) => {
                 let mut err = struct_span_err!(self.sess(), span, E0034,
                                                "multiple applicable items in scope");
+                err.span_label(span, &format!("multiple `{}` found", item_name));
 
                 report_candidates(&mut err, sources);
                 err.emit();

src/test/compile-fail/E0034.rs

@@ -18,9 +18,17 @@ trait Trait2 {
     fn foo();
 }
 
-impl Trait1 for Test { fn foo() {} }
-impl Trait2 for Test { fn foo() {} }
+impl Trait1 for Test {
+    fn foo() {}
+    //~^ NOTE candidate #1 is defined in an impl of the trait `Trait1` for the type `Test`
+}
+
+impl Trait2 for Test {
+    fn foo() {}
+    //~^ NOTE candidate #2 is defined in an impl of the trait `Trait2` for the type `Test`
+}
 
 fn main() {
-    Test::foo() //~ ERROR E0034
+    Test::foo() //~ ERROR multiple applicable items in scope
+    //~| NOTE multiple `foo` found
 }