Rollup merge of #106097 - mejrs:mir_build2, r=oli-obk

Migrate mir_build diagnostics 2 of 3

The first three commits are fairly boring, however I've made some changes to the output of the match checking diagnostics.

tests/ui/error-codes/E0005.stderr

@@ -1,4 +1,4 @@
-error[E0005]: refutable pattern in local binding: `None` not covered
+error[E0005]: refutable pattern in local binding
   --> $DIR/E0005.rs:3:9
    |
 LL |     let Some(y) = x;
@@ -6,17 +6,8 @@ LL |     let Some(y) = x;
    |
    = note: `let` bindings require an "irrefutable pattern", like a `struct` or an `enum` with only one variant
    = note: for more information, visit https://doc.rust-lang.org/book/ch18-02-refutability.html
-note: `Option<i32>` defined here
-  --> $SRC_DIR/core/src/option.rs:LL:COL
-  ::: $SRC_DIR/core/src/option.rs:LL:COL
-   |
-   = note: not covered
    = note: the matched value is of type `Option<i32>`
-help: you might want to use `if let` to ignore the variant that isn't matched
-   |
-LL |     let y = if let Some(y) = x { y } else { todo!() };
-   |     ++++++++++                 ++++++++++++++++++++++
-help: alternatively, you might want to use let else to handle the variant that isn't matched
+help: you might want to use `let else` to handle the variant that isn't matched
    |
 LL |     let Some(y) = x else { todo!() };
    |                     ++++++++++++++++

tests/ui/error-codes/E0297.stderr

@@ -1,14 +1,9 @@
-error[E0005]: refutable pattern in `for` loop binding: `None` not covered
+error[E0005]: refutable pattern in `for` loop binding
   --> $DIR/E0297.rs:4:9
    |
 LL |     for Some(x) in xs {}
    |         ^^^^^^^ pattern `None` not covered
    |
-note: `Option<i32>` defined here
-  --> $SRC_DIR/core/src/option.rs:LL:COL
-  ::: $SRC_DIR/core/src/option.rs:LL:COL
-   |
-   = note: not covered
    = note: the matched value is of type `Option<i32>`
 
 error: aborting due to previous error