typeck: port "no resolve overridden impl substs"

Port "could not resolve substs on overridden impl" diagnostic to use the
diagnostic derive.

Signed-off-by: David Wood <david.wood@huawei.com>

Author: davidtwco

compiler/rustc_error_messages/locales/en-US/typeck.ftl

@@ -127,3 +127,5 @@ typeck-manual-implementation =
     manual implementations of `{$trait_name}` are experimental
     .label = manual implementations of `{$trait_name}` are experimental
     .help = add `#![feature(unboxed_closures)]` to the crate attributes to enable
+
+typeck-substs-on-overridden-impl = could not resolve substs on overridden impl

compiler/rustc_typeck/src/errors.rs

@@ -323,3 +323,10 @@ pub struct ManualImplementation {
     pub span: Span,
     pub trait_name: String,
 }
+
+#[derive(SessionDiagnostic)]
+#[error(slug = "typeck-substs-on-overridden-impl")]
+pub struct SubstsOnOverriddenImpl {
+    #[primary_span]
+    pub span: Span,
+}

compiler/rustc_typeck/src/impl_wf_check/min_specialization.rs

@@ -66,6 +66,7 @@
 //! on traits with methods can.
 
 use crate::constrained_generic_params as cgp;
+use crate::errors::SubstsOnOverriddenImpl;
 
 use rustc_data_structures::fx::FxHashSet;
 use rustc_hir::def_id::{DefId, LocalDefId};
@@ -165,7 +166,7 @@ fn get_impl_substs<'tcx>(
     let outlives_env = OutlivesEnvironment::new(ty::ParamEnv::empty());
     infcx.resolve_regions_and_report_errors(impl1_def_id, &outlives_env, RegionckMode::default());
     let Ok(impl2_substs) = infcx.fully_resolve(impl2_substs) else {
-        tcx.sess.struct_span_err(span, "could not resolve substs on overridden impl").emit();
+        tcx.sess.emit_err(SubstsOnOverriddenImpl { span });
         return None;
     };
     Some((impl1_substs, impl2_substs))