Unify wording of resolve error

Remove "failed to resolve" and use the same format we use in other resolution errors "cannot find `name`".

```
error[E0433]: cannot find `nonexistent` in `existent`
  --> $DIR/custom_attr_multisegment_error.rs:5:13
   |
LL | #[existent::nonexistent]
   |             ^^^^^^^^^^^ could not find `nonexistent` in `existent`
```

Author: estebank

tests/ui/crashes/unreachable-array-or-slice.rs

@@ -2,7 +2,7 @@ struct Foo(isize, isize, isize, isize);
 
 pub fn main() {
     let Self::anything_here_kills_it(a, b, ..) = Foo(5, 5, 5, 5);
-    //~^ ERROR: failed to resolve
+    //~^ ERROR: cannot find `Self` in this scope
     match [5, 5, 5, 5] {
         [..] => {},
     }

tests/ui/crashes/unreachable-array-or-slice.stderr

@@ -1,4 +1,4 @@
-error[E0433]: failed to resolve: `Self` is only available in impls, traits, and type definitions
+error[E0433]: cannot find `Self` in this scope
   --> tests/ui/crashes/unreachable-array-or-slice.rs:4:9
    |
 LL |     let Self::anything_here_kills_it(a, b, ..) = Foo(5, 5, 5, 5);