Auto merge of #1210 - RalfJung:rustup-validity, r=RalfJung

rustup: adjust error message

This is the Miri side of rust-lang/rust#69762

Author: bors

Diff for: rust-version

@@ -1 +1 @@
-7a3700c37132385e8e965c18e73d0a09f9146335
+3dbade652ed8ebac70f903e01f51cd92c4e4302c

Diff for: tests/compile-fail/slice-too-big.rs

@@ -2,5 +2,5 @@ use std::mem;
 
 fn main() { unsafe {
     let ptr = Box::into_raw(Box::new(0u8));
-    let _x: &[u8] = mem::transmute((ptr, usize::MAX)); //~ ERROR: invalid slice: total size is bigger than largest supported object
+    let _x: &[u8] = mem::transmute((ptr, usize::MAX)); //~ ERROR: invalid reference metadata: slice is bigger than largest supported object
 } }