Update std and compiler

compiler/rustc_transmute/src/layout/nfa.rs

@@ -87,6 +87,7 @@ where
     pub(crate) fn from_tree(tree: Tree<!, R>) -> Result<Self, Uninhabited> {
         Ok(match tree {
             Tree::Byte(b) => Self::from_byte(b),
+            #[cfg(bootstrap)]
             Tree::Def(..) => unreachable!(),
             Tree::Ref(r) => Self::from_ref(r),
             Tree::Alt(alts) => {