Address irrefutable while let diagnostic review

Author: anoshyn

compiler/rustc_hir_typeck/src/coercion.rs

@@ -1895,11 +1895,11 @@ impl<'tcx> CoerceMany<'tcx> {
 
                         err.note(format!("{loop_type} evaluate to unit type `()`"));
                         if loop_src == hir::LoopSource::While
-                            && let Some(pat) = irrefutable_while_let_pattern(block)
+                            && let Some(pat) = irrefutable_if_let_expr(block)
                         {
                             err.span_note(
                                 pat.span,
-                                "this pattern always matches, so the loop condition never fails",
+                                "this pattern always matches, consider using `loop` instead",
                             );
                         }
                     }
@@ -2134,7 +2134,7 @@ impl<'tcx> CoerceMany<'tcx> {
     }
 }
 
-fn irrefutable_while_let_pattern<'hir>(block: &hir::Block<'hir>) -> Option<&'hir hir::Pat<'hir>> {
+fn irrefutable_if_let_expr<'hir>(block: &hir::Block<'hir>) -> Option<&'hir hir::Pat<'hir>> {
     let hir::ExprKind::If(cond, _, _) = block.expr?.kind else {
         return None;
     };

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

@@ -182,7 +182,7 @@ LL | |     }
    | |_____^ expected `bool`, found `()`
    |
    = note: `while` loops evaluate to unit type `()`
-note: this pattern always matches, so the loop condition never fails
+note: this pattern always matches, consider using `loop` instead
   --> $DIR/coerce-loop-issue-122561.rs:73:15
    |
 LL |     while let x = false {
@@ -207,7 +207,7 @@ LL | |     }
    | |_____^ expected `bool`, found `()`
    |
    = note: `while` loops evaluate to unit type `()`
-note: this pattern always matches, so the loop condition never fails
+note: this pattern always matches, consider using `loop` instead
   --> $DIR/coerce-loop-issue-122561.rs:82:15
    |
 LL |     while let (x, _) = (false, true) {