Point at method call when type annotations are needed

src/test/ui/associated-types/associated-types-overridden-binding.stderr

@@ -1,18 +1,23 @@
-error[E0284]: type annotations needed: cannot resolve `<Self as std::iter::Iterator>::Item == i32`
+error[E0284]: type annotations needed
   --> $DIR/associated-types-overridden-binding.rs:4:1
    |
 LL | trait Foo: Iterator<Item = i32> {}
    | ------------------------------- required by `Foo`
 LL | trait Bar: Foo<Item = u32> {}
-   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ cannot infer type for `Self`
+   |
+   = note: cannot resolve `<Self as std::iter::Iterator>::Item == i32`
 
-error[E0282]: type annotations needed
+error[E0284]: type annotations needed
   --> $DIR/associated-types-overridden-binding.rs:7:1
    |
+LL | trait I32Iterator = Iterator<Item = i32>;
+   | ----------------------------------------- required by `I32Iterator`
 LL | trait U32Iterator = I32Iterator<Item = u32>;
-   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ cannot infer type
+   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ cannot infer type for `Self`
+   |
+   = note: cannot resolve `<Self as std::iter::Iterator>::Item == i32`
 
 error: aborting due to 2 previous errors
 
-Some errors have detailed explanations: E0282, E0284.
-For more information about an error, try `rustc --explain E0282`.
+For more information about this error, try `rustc --explain E0284`.

src/test/ui/associated-types/associated-types-unconstrained.stderr

@@ -1,8 +1,10 @@
-error[E0284]: type annotations needed: cannot resolve `<_ as Foo>::A == _`
+error[E0284]: type annotations needed
   --> $DIR/associated-types-unconstrained.rs:14:20
    |
 LL |     let x: isize = Foo::bar();
-   |                    ^^^^^^^^
+   |                    ^^^^^^^^ cannot infer type
+   |
+   = note: cannot resolve `<_ as Foo>::A == _`
 
 error: aborting due to previous error
 

src/test/ui/issues/issue-12028.stderr

@@ -1,8 +1,10 @@
-error[E0284]: type annotations needed: cannot resolve `<_ as StreamHasher>::S == <H as StreamHasher>::S`
+error[E0284]: type annotations needed
   --> $DIR/issue-12028.rs:27:14
    |
 LL |         self.input_stream(&mut stream);
-   |              ^^^^^^^^^^^^
+   |              ^^^^^^^^^^^^ cannot infer type for `H`
+   |
+   = note: cannot resolve `<_ as StreamHasher>::S == <H as StreamHasher>::S`
 
 error: aborting due to previous error
 

src/test/ui/issues/issue-65611.stderr

@@ -2,7 +2,10 @@ error[E0282]: type annotations needed
   --> $DIR/issue-65611.rs:59:20
    |
 LL |     let x = buffer.last().unwrap().0.clone();
-   |                    ^^^^ cannot infer type for `T`
+   |                    ^^^^
+   |                    |
+   |                    cannot infer type for `T`
+   |                    help: consider specifying the type argument in the method call: `last::<_>`
    |
    = note: type must be known at this point
 

src/test/ui/question-mark-type-infer.rs

@@ -9,7 +9,7 @@ fn f(x: &i32) -> Result<i32, ()> {
 
 fn g() -> Result<Vec<i32>, ()> {
     let l = [1, 2, 3, 4];
-    l.iter().map(f).collect()? //~ ERROR type annotations needed: cannot resolve
+    l.iter().map(f).collect()? //~ ERROR type annotations needed
 }
 
 fn main() {

src/test/ui/question-mark-type-infer.stderr

@@ -1,8 +1,13 @@
-error[E0284]: type annotations needed: cannot resolve `<_ as std::ops::Try>::Ok == _`
-  --> $DIR/question-mark-type-infer.rs:12:5
+error[E0284]: type annotations needed
+  --> $DIR/question-mark-type-infer.rs:12:21
    |
 LL |     l.iter().map(f).collect()?
-   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^
+   |                     ^^^^^^^
+   |                     |
+   |                     cannot infer type
+   |                     help: consider specifying the type argument in the method call: `collect::<_>`
+   |
+   = note: cannot resolve `<_ as std::ops::Try>::Ok == _`
 
 error: aborting due to previous error
 

src/test/ui/span/issue-42234-unknown-receiver-type.rs

@@ -9,8 +9,8 @@ fn shines_a_beacon_through_the_darkness() {
 }
 
 fn courier_to_des_moines_and_points_west(data: &[u32]) -> String {
-    data.iter() //~ ERROR type annotations needed
-        .sum::<_>()
+    data.iter()
+        .sum::<_>() //~ ERROR type annotations needed
         .to_string()
 }
 

src/test/ui/span/issue-42234-unknown-receiver-type.stderr

@@ -9,11 +9,10 @@ LL |     x.unwrap().method_that_could_exist_on_some_type();
    = note: type must be known at this point
 
 error[E0282]: type annotations needed
-  --> $DIR/issue-42234-unknown-receiver-type.rs:12:5
+  --> $DIR/issue-42234-unknown-receiver-type.rs:13:10
    |
-LL | /     data.iter()
-LL | |         .sum::<_>()
-   | |___________________^ cannot infer type
+LL |         .sum::<_>()
+   |          ^^^ cannot infer type
    |
    = note: type must be known at this point
 

src/test/ui/span/type-annotations-needed-expr.stderr

@@ -2,7 +2,10 @@ error[E0282]: type annotations needed
   --> $DIR/type-annotations-needed-expr.rs:2:39
    |
 LL |     let _ = (vec![1,2,3]).into_iter().sum() as f64;
-   |                                       ^^^ cannot infer type for `S`
+   |                                       ^^^
+   |                                       |
+   |                                       cannot infer type for `S`
+   |                                       help: consider specifying the type argument in the method call: `sum::<_>`
    |
    = note: type must be known at this point