Ignore some doctests that are incompatible with current --stage=0

These changes can be reverted during the next bootstrap bump.

Author: Zalathar

compiler/rustc_lint/src/if_let_rescope.rs

@@ -23,7 +23,8 @@ declare_lint! {
     ///
     /// ### Example
     ///
-    /// ```rust,edition2021
+    #[cfg_attr(bootstrap, doc = "```ignore")]
+    #[cfg_attr(not(bootstrap), doc = "```rust,edition2021")]
     /// #![feature(if_let_rescope)]
     /// #![warn(if_let_rescope)]
     /// #![allow(unused_variables)]
@@ -54,7 +55,7 @@ declare_lint! {
     ///         // do something else
     ///     }
     /// }
-    /// ```
+    #[doc = "```"] // #[cfg_attr(not(bootstrap), ..)] // Needed to satisfy tidy; revert after bootstrap bump.
     ///
     /// {{produces}}
     ///

compiler/rustc_lint_defs/src/builtin.rs

@@ -1870,15 +1870,16 @@ declare_lint! {
     ///
     /// ### Example
     ///
-    /// ```rust,compile_fail
+    #[cfg_attr(bootstrap, doc = "```ignore")]
+    #[cfg_attr(not(bootstrap), doc = "```rust,compile_fail")]
     /// #![deny(elided_named_lifetimes)]
     /// struct Foo;
     /// impl Foo {
     ///     pub fn get_mut(&'static self, x: &mut u8) -> &mut u8 {
     ///         unsafe { &mut *(x as *mut _) }
     ///     }
     /// }
-    /// ```
+    #[doc = "```"] // #[cfg_attr(not(bootstrap), ..)] // Needed to satisfy tidy; revert after bootstrap bump.
     ///
     /// {{produces}}
     ///