error[E0594]: cannot assign to `*ptr`, which is behind a `*const` pointer
  --> $DIR/dont_suggest_raw_pointer_syntax-issue-127562.rs:5:9
   |
LL |         *ptr = 3;
   |         ^^^^^^^^ `ptr` is a `*const` pointer, so the data it refers to cannot be written

error: aborting due to 1 previous error

For more information about this error, try `rustc --explain E0594`.