Auto merge of #102950 - oli-obk:check_miri, r=RalfJung

Enable `x.py check` for miri

Now that the miri subtree is working properly, let's add it to x.py check.

cc `@rust-lang/miri`

Author: bors

src/lib.rs

@@ -38,6 +38,8 @@
     clippy::cast_lossless,
     clippy::cast_possible_truncation,
 )]
+// Needed for rustdoc from bootstrap (with `-Znormalize-docs`).
+#![recursion_limit = "256"]
 
 extern crate rustc_apfloat;
 extern crate rustc_ast;