Auto merge of #118443 - matthiaskrgr:rollup-mp8o3m4, r=matthiaskrgr

Rollup of 7 pull requests

Successful merges:

 - #118157 (Add `never_patterns` feature gate)
 - #118191 (Suggest `let` or `==` on typo'd let-chain)
 - #118231 (also add is_empty to const raw slices)
 - #118333 (Print list of missing target features when calling a function with target features outside an unsafe block)
 - #118426 (ConstProp: Correctly remove const if unknown value assigned to it.)
 - #118428 (rustdoc: Move `AssocItemRender` and `RenderMode` to `html::render`.)
 - #118438 (Update nto-qnx.md)

Failed merges:

 - #118268 (Pretty print `Fn<(..., ...)>` trait refs with parentheses (almost) always)

r? `@ghost`
`@rustbot` modify labels: rollup

1 files changed, 26 insertions, 0 deletions

diff --git a/compiler/rustc_parse/src/errors.rs b/compiler/rustc_parse/src/errors.rs
index 0a919240ce5..e5d4cb6f4da 100644
--- a/compiler/rustc_parse/src/errors.rs
+++ b/compiler/rustc_parse/src/errors.rs
@@ -415,6 +415,32 @@ pub(crate) struct ExpectedExpressionFoundLet {
     pub span: Span,
     #[subdiagnostic]
     pub reason: ForbiddenLetReason,
+    #[subdiagnostic]
+    pub missing_let: Option<MaybeMissingLet>,
+    #[subdiagnostic]
+    pub comparison: Option<MaybeComparison>,
+}
+
+#[derive(Subdiagnostic, Clone, Copy)]
+#[multipart_suggestion(
+    parse_maybe_missing_let,
+    applicability = "maybe-incorrect",
+    style = "verbose"
+)]
+pub(crate) struct MaybeMissingLet {
+    #[suggestion_part(code = "let ")]
+    pub span: Span,
+}
+
+#[derive(Subdiagnostic, Clone, Copy)]
+#[multipart_suggestion(
+    parse_maybe_comparison,
+    applicability = "maybe-incorrect",
+    style = "verbose"
+)]
+pub(crate) struct MaybeComparison {
+    #[suggestion_part(code = "=")]
+    pub span: Span,
 }
 
 #[derive(Diagnostic)]