error[E0530]: match bindings cannot shadow constants
  --> $DIR/issue-34047.rs:5:13
   |
LL | const C: u8 = 0;
   | ---------------- the constant `C` is defined here
...
LL |         mut C => {}
   |             ^ cannot be named the same as a constant

error: aborting due to previous error

For more information about this error, try `rustc --explain E0530`.