minor simplification

src/lvalue.rs

@@ -355,8 +355,10 @@ impl<'a, 'tcx> EvalContext<'a, 'tcx> {
                 extra: LvalueExtra::None,
             })
         } else {
-            let ptr_primval = match (base_ptr.to_ptr(), elem_size) {
-                (Ok(p), _) => {
+            let ptr_primval = if elem_size == 0 {
+                base_ptr
+            } else {
+                let p = base_ptr.to_ptr()?;
                 let byte_index = self.memory.constraints.add_binop_constraint(
                     mir::BinOp::Mul,
                     idx,
@@ -369,9 +371,6 @@ impl<'a, 'tcx> EvalContext<'a, 'tcx> {
                     byte_index,
                     PrimValKind::U64);
                 PrimVal::Ptr(Pointer::with_primval_offset(p.alloc_id, offset))
-                }
-                (Err(_), 0) => base_ptr,
-                (Err(e), _) => return Err(e),
             };
 
             Ok(Lvalue::Ptr {