Label irrefutable while let pattern diagnostic

Author: anoshyn

compiler/rustc_hir_typeck/src/coercion.rs

@@ -1897,7 +1897,7 @@ impl<'tcx> CoerceMany<'tcx> {
                         if loop_src == hir::LoopSource::While
                             && let Some(pat) = irrefutable_if_let_expr(block)
                         {
-                            err.span_note(
+                            err.span_label(
                                 pat.span,
                                 "this pattern always matches, consider using `loop` instead",
                             );

tests/ui/coercion/coerce-loop-issue-122561.stderr

@@ -173,7 +173,10 @@ error[E0308]: mismatched types
    |
 LL |   fn while_let_binding() -> bool {
    |                             ---- expected `bool` because of return type
-LL | /     while let x = false {
+LL |       while let x = false {
+   |       ^         - this pattern always matches, consider using `loop` instead
+   |  _____|
+   | |
 LL | |
 LL | |         if x {
 LL | |             return true;
@@ -182,11 +185,6 @@ LL | |     }
    | |_____^ expected `bool`, found `()`
    |
    = note: `while` loops evaluate to unit type `()`
-note: this pattern always matches, consider using `loop` instead
-  --> $DIR/coerce-loop-issue-122561.rs:73:15
-   |
-LL |     while let x = false {
-   |               ^
 help: consider returning a value here
    |
 LL ~     }
@@ -198,7 +196,10 @@ error[E0308]: mismatched types
    |
 LL |   fn while_let_tuple() -> bool {
    |                           ---- expected `bool` because of return type
-LL | /     while let (x, _) = (false, true) {
+LL |       while let (x, _) = (false, true) {
+   |       ^         ------ this pattern always matches, consider using `loop` instead
+   |  _____|
+   | |
 LL | |
 LL | |         if x {
 LL | |             return true;
@@ -207,11 +208,6 @@ LL | |     }
    | |_____^ expected `bool`, found `()`
    |
    = note: `while` loops evaluate to unit type `()`
-note: this pattern always matches, consider using `loop` instead
-  --> $DIR/coerce-loop-issue-122561.rs:82:15
-   |
-LL |     while let (x, _) = (false, true) {
-   |               ^^^^^^
 help: consider returning a value here
    |
 LL ~     }