error: Undefined Behavior: interpreting an invalid 32-bit value as a char: $HEX
  --> tests/fail/validity/invalid_char_match.rs:LL:CC
   |
LL | /             match *ptr {
LL | |                 '0' => ret,
LL | |                 _ => ret,
LL | |             }
   | |_____________^ Undefined Behavior occurred here
   |
   = 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: BACKTRACE:
   = note: inside `switch_int` at tests/fail/validity/invalid_char_match.rs:LL:CC
note: inside `main`
  --> tests/fail/validity/invalid_char_match.rs:LL:CC
   |
LL |     switch_int(&v as *const u32 as *const char);
   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

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

error: aborting due to 1 previous error