Rollup merge of #150458 - RalfJung:miri-doctests, r=bjorn3

fix running stdlib doctests in Miri in CI

r? `@bjorn3`

library/core/src/mem/maybe_dangling.rs

@@ -36,7 +36,8 @@ use crate::{mem, ptr};
 ///
 /// To fix this we could use `MaybeDangling`:
 ///
-/// ```rust
+// FIXME: remove `no_run` once the semantics are actually implemented
+/// ```rust,no_run
 /// #![feature(maybe_dangling, box_as_ptr)]
 /// # use std::alloc::{dealloc, Layout};
 /// # use std::mem::{self, MaybeDangling};

src/bootstrap/mk/Makefile.in

@@ -56,8 +56,7 @@ check-aux:
 	# Run standard library tests in Miri.
 	$(Q)MIRIFLAGS="-Zmiri-strict-provenance" \
 		$(BOOTSTRAP) miri --stage 2 \
-		library/coretests \
-		library/alloctests \
+		library/core \
 		library/alloc \
 		$(BOOTSTRAP_ARGS) \
 		--no-doc
@@ -65,8 +64,7 @@ check-aux:
 	# so we have to run them with isolation disabled.
 	$(Q)MIRIFLAGS="-Zmiri-disable-isolation" \
 		$(BOOTSTRAP) miri --stage 2 \
-		library/coretests \
-		library/alloctests \
+		library/core \
 		library/alloc \
 		$(BOOTSTRAP_ARGS) \
 		--doc