borrow check of FRTs (have no fields & can't be dereferenced)

Author: BennoLossin

compiler/rustc_borrowck/src/lib.rs

@@ -1893,6 +1893,7 @@ impl<'a, 'tcx> MirBorrowckCtxt<'a, '_, 'tcx> {
                         }
                     }
                     ty::Bool
+                    | ty::Field(..)
                     | ty::Char
                     | ty::Int(_)
                     | ty::Uint(_)
@@ -1937,6 +1938,7 @@ impl<'a, 'tcx> MirBorrowckCtxt<'a, '_, 'tcx> {
                     | ty::Coroutine(_, _)
                     | ty::Tuple(_) => (),
                     ty::Bool
+                    | ty::Field(..)
                     | ty::Char
                     | ty::Int(_)
                     | ty::Uint(_)