remove `has_error_field` helper method

compiler/rustc_hir_analysis/src/check/wfcheck.rs

@@ -1745,9 +1745,11 @@ fn check_variances_for_type_defn<'tcx>(
     item: &hir::Item<'tcx>,
     hir_generics: &hir::Generics<'_>,
 ) {
-    let ty = tcx.type_of(item.owner_id).subst_identity();
-    if tcx.has_error_field(ty) {
-        return;
+    let identity_substs = ty::InternalSubsts::identity_for_item(tcx, item.owner_id);
+    for field in tcx.adt_def(item.owner_id).all_fields() {
+        if field.ty(tcx, identity_substs).references_error() {
+            return;
+        }
     }
 
     let ty_predicates = tcx.predicates_of(item.owner_id);

compiler/rustc_middle/src/ty/util.rs

@@ -173,18 +173,6 @@ impl<'tcx> TyCtxt<'tcx> {
         }
     }
 
-    pub fn has_error_field(self, ty: Ty<'tcx>) -> bool {
-        if let ty::Adt(def, substs) = *ty.kind() {
-            for field in def.all_fields() {
-                let field_ty = field.ty(self, substs);
-                if let ty::Error(_) = field_ty.kind() {
-                    return true;
-                }
-            }
-        }
-        false
-    }
-
     /// Attempts to returns the deeply last field of nested structures, but
     /// does not apply any normalization in its search. Returns the same type
     /// if input `ty` is not a structure at all.

tests/ui/const-generics/const-param-type-depends-on-type-param.full.stderr

@@ -6,16 +6,6 @@ LL | pub struct Dependent<T, const X: T>([(); X]);
    |
    = note: type parameters may not be used in the type of const parameters
 
-error[E0392]: parameter `T` is never used
-  --> $DIR/const-param-type-depends-on-type-param.rs:11:22
-   |
-LL | pub struct Dependent<T, const X: T>([(); X]);
-   |                      ^ unused parameter
-   |
-   = help: consider removing `T`, referring to it in a field, or using a marker such as `PhantomData`
-   = help: if you intended `T` to be a const parameter, use `const T: usize` instead
+error: aborting due to previous error
 
-error: aborting due to 2 previous errors
-
-Some errors have detailed explanations: E0392, E0770.
-For more information about an error, try `rustc --explain E0392`.
+For more information about this error, try `rustc --explain E0770`.

tests/ui/const-generics/const-param-type-depends-on-type-param.min.stderr

@@ -6,16 +6,6 @@ LL | pub struct Dependent<T, const X: T>([(); X]);
    |
    = note: type parameters may not be used in the type of const parameters
 
-error[E0392]: parameter `T` is never used
-  --> $DIR/const-param-type-depends-on-type-param.rs:11:22
-   |
-LL | pub struct Dependent<T, const X: T>([(); X]);
-   |                      ^ unused parameter
-   |
-   = help: consider removing `T`, referring to it in a field, or using a marker such as `PhantomData`
-   = help: if you intended `T` to be a const parameter, use `const T: usize` instead
+error: aborting due to previous error
 
-error: aborting due to 2 previous errors
-
-Some errors have detailed explanations: E0392, E0770.
-For more information about an error, try `rustc --explain E0392`.
+For more information about this error, try `rustc --explain E0770`.

tests/ui/const-generics/const-param-type-depends-on-type-param.rs

@@ -10,6 +10,5 @@
 
 pub struct Dependent<T, const X: T>([(); X]);
 //~^ ERROR: the type of const parameters must not depend on other generic parameters
-//~| ERROR: parameter `T` is never used
 
 fn main() {}