skip const eval if we have an error in borrowck

compiler/rustc_middle/src/ty/context.rs

@@ -8,7 +8,9 @@ use crate::lint::{struct_lint_level, LintDiagnosticBuilder, LintLevelSource};
 use crate::middle::resolve_lifetime::{self, LifetimeScopeForPath};
 use crate::middle::stability;
 use crate::mir::interpret::{self, Allocation, ConstValue, Scalar};
-use crate::mir::{Body, Field, Local, Place, PlaceElem, ProjectionKind, Promoted};
+use crate::mir::{
+    Body, BorrowCheckResult, Field, Local, Place, PlaceElem, ProjectionKind, Promoted,
+};
 use crate::thir::Thir;
 use crate::traits;
 use crate::ty::query::{self, TyCtxtAt};
@@ -1061,6 +1063,17 @@ impl<'tcx> TyCtxt<'tcx> {
         }
     }
 
+    pub fn mir_borrowck_opt_const_arg(
+        self,
+        def: ty::WithOptConstParam<LocalDefId>,
+    ) -> &'tcx BorrowCheckResult<'tcx> {
+        if let Some(param_did) = def.const_param_did {
+            self.mir_borrowck_const_arg((def.did, param_did))
+        } else {
+            self.mir_borrowck(def.did)
+        }
+    }
+
     pub fn alloc_steal_thir(self, thir: Thir<'tcx>) -> &'tcx Steal<Thir<'tcx>> {
         self.arena.alloc(Steal::new(thir))
     }