future-compat lint for newly handled cases of #[structural_match].

Author: pnkfelix

src/librustc/lint/builtin.rs

@@ -346,6 +346,12 @@ declare_lint! {
     "outlives requirements can be inferred"
 }
 
+declare_lint! {
+    pub INDIRECT_STRUCTURAL_MATCH,
+    Warn,
+    "pattern with const indirectly referencing non-`#[structural_match]` type"
+}
+
 /// Some lints that are buffered from `libsyntax`. See `syntax::early_buffered_lints`.
 pub mod parser {
     declare_lint! {

src/librustc_lint/lib.rs

@@ -427,6 +427,11 @@ pub fn register_builtins(store: &mut lint::LintStore, sess: Option<&Session>) {
             id: LintId::of(MUTABLE_BORROW_RESERVATION_CONFLICT),
             reference: "issue #59159 <https://github.com/rust-lang/rust/issues/59159>",
             edition: None,
+        },
+        FutureIncompatibleInfo {
+            id: LintId::of(INDIRECT_STRUCTURAL_MATCH),
+            reference: "issue #62411 <https://github.com/rust-lang/rust/issues/62411>",
+            edition: None,
         }
         ]);