error: Undefined Behavior: type validation failed: encountered invalid reference metadata: slice is bigger than largest supported object
  --> $DIR/slice-too-big.rs:5:21
   |
LL |     let _x: &[u8] = mem::transmute((ptr, usize::MAX)); //~ ERROR: invalid reference metadata: slice is bigger than largest supported object
   |                     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ type validation failed: encountered invalid reference metadata: slice is bigger than largest supported object
   |
   = help: this indicates a bug in the program: it performed an invalid operation, and caused Undefined Behavior
   = help: see https://doc.rust-lang.org/nightly/reference/behavior-considered-undefined.html for further information
           
   = note: inside `main` at $DIR/slice-too-big.rs:5:21

note: some details are omitted, run with `MIRIFLAGS=-Zmiri-backtrace=full` for a verbose backtrace

error: aborting due to previous error