Point to correct argument in Func Call when Self type fails trait bound

When a trait bound fails due to the Self type parameter, adjust_fulfillment_errors
now correctly points to the corresponding function argument instead of incorrectly
pointing to other arguments.

Signed-off-by: xizheyin <xizheyin@smail.nju.edu.cn>

Author: xizheyin

compiler/rustc_hir_typeck/src/fn_ctxt/adjust_fulfillment_errors.rs

@@ -184,9 +184,14 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
                     return true;
                 }
 
-                for param in [param_to_point_at, fallback_param_to_point_at, self_param_to_point_at]
-                    .into_iter()
-                    .flatten()
+                for param in [
+                    predicate_self_type_to_point_at,
+                    param_to_point_at,
+                    fallback_param_to_point_at,
+                    self_param_to_point_at,
+                ]
+                .into_iter()
+                .flatten()
                 {
                     if self.blame_specific_arg_if_possible(
                         error,

tests/ui/associated-type-bounds/dedup-normalized-2-higher-ranked.current.stderr

@@ -2,7 +2,9 @@ error[E0283]: type annotations needed
   --> $DIR/dedup-normalized-2-higher-ranked.rs:28:5
    |
 LL |     impls(rigid);
-   |     ^^^^^ cannot infer type of the type parameter `U` declared on the function `impls`
+   |     ^^^^^ ----- type must be known at this point
+   |     |
+   |     cannot infer type of the type parameter `U` declared on the function `impls`
    |
    = note: cannot satisfy `for<'b> <P as Trait>::Rigid: Bound<'b, _>`
 note: required by a bound in `impls`

tests/ui/const-generics/infer/issue-77092.stderr

@@ -20,7 +20,7 @@ error[E0284]: type annotations needed
 LL |         println!("{:?}", take_array_from_mut(&mut arr, i));
    |                   ----   ^^^^^^^^^^^^^^^^^^^ cannot infer the value of the const parameter `N` declared on the function `take_array_from_mut`
    |                   |
-   |                   type must be known at this point
+   |                   required by this formatting parameter
    |
    = note: required for `[i32; _]` to implement `Debug`
    = note: 1 redundant requirement hidden

tests/ui/impl-trait/auto-trait-selection-freeze.old.stderr

@@ -2,7 +2,9 @@ error[E0283]: type annotations needed
   --> $DIR/auto-trait-selection-freeze.rs:19:16
    |
 LL |     if false { is_trait(foo()) } else { Default::default() }
-   |                ^^^^^^^^ cannot infer type of the type parameter `U` declared on the function `is_trait`
+   |                ^^^^^^^^ ----- type must be known at this point
+   |                |
+   |                cannot infer type of the type parameter `U` declared on the function `is_trait`
    |
 note: multiple `impl`s satisfying `impl Sized: Trait<_>` found
   --> $DIR/auto-trait-selection-freeze.rs:16:1

tests/ui/impl-trait/auto-trait-selection.old.stderr

@@ -2,7 +2,9 @@ error[E0283]: type annotations needed
   --> $DIR/auto-trait-selection.rs:15:16
    |
 LL |     if false { is_trait(foo()) } else { Default::default() }
-   |                ^^^^^^^^ cannot infer type of the type parameter `U` declared on the function `is_trait`
+   |                ^^^^^^^^ ----- type must be known at this point
+   |                |
+   |                cannot infer type of the type parameter `U` declared on the function `is_trait`
    |
 note: multiple `impl`s satisfying `impl Sized: Trait<_>` found
   --> $DIR/auto-trait-selection.rs:12:1

tests/ui/trait-bounds/false-span-in-trait-bound-label.rs

@@ -1,10 +1,10 @@
 // In this test, the span of the trait bound label should point to `1`, not `""`.
-// See issue #1433376
+// See issue #143336
 
 trait A<T> {
     fn f(self, x: T);
 }
 
 fn main() {
     A::f(1, ""); //~ ERROR the trait bound `{integer}: A<_>` is not satisfied [E0277]
-}
+}

tests/ui/trait-bounds/false-span-in-trait-bound-label.stderr

@@ -1,8 +1,8 @@
 error[E0277]: the trait bound `{integer}: A<_>` is not satisfied
-  --> $DIR/false-span-in-trait-bound-label.rs:9:13
+  --> $DIR/false-span-in-trait-bound-label.rs:9:10
    |
 LL |     A::f(1, "");
-   |     ----    ^^ the trait `A<_>` is not implemented for `{integer}`
+   |     ---- ^ the trait `A<_>` is not implemented for `{integer}`
    |     |
    |     required by a bound introduced by this call
    |

tests/ui/traits/inheritance/repeated-supertrait-ambig.stderr

@@ -34,10 +34,10 @@ LL |     <dyn CompareToInts>::same_as(c, 22)
              `i64` implements `CompareTo<u64>`
 
 error[E0277]: the trait bound `C: CompareTo<i32>` is not satisfied
-  --> $DIR/repeated-supertrait-ambig.rs:38:27
+  --> $DIR/repeated-supertrait-ambig.rs:38:24
    |
 LL |     CompareTo::same_as(c, 22)
-   |     ------------------    ^^ the trait `CompareTo<i32>` is not implemented for `C`
+   |     ------------------ ^ the trait `CompareTo<i32>` is not implemented for `C`
    |     |
    |     required by a bound introduced by this call
    |

tests/ui/traits/multidispatch-convert-ambig-dest.stderr

@@ -2,7 +2,7 @@ error[E0283]: type annotations needed
   --> $DIR/multidispatch-convert-ambig-dest.rs:26:5
    |
 LL |     test(22, std::default::Default::default());
-   |     ^^^^     -------------------------------- type must be known at this point
+   |     ^^^^ -- type must be known at this point
    |     |
    |     cannot infer type of the type parameter `U` declared on the function `test`
    |