error: Undefined Behavior: `float_to_int_unchecked` intrinsic called on 1.8446744073709552E+19 which cannot be represented in target type `u64`
  --> $DIR/float_to_int_64_too_big3.rs:LL:CC
   |
LL |         float_to_int_unchecked::<f64, u64>(18446744073709551616.0f64);
   |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ `float_to_int_unchecked` intrinsic called on 1.8446744073709552E+19 which cannot be represented in target type `u64`
   |
   = 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 `main` at $DIR/float_to_int_64_too_big3.rs:LL:CC

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

error: aborting due to previous error