Documentation error at Basics.Int (source):
of that range, the behavior is determined by the compilation target. When
generating JavaScript, the safe range expands to `-2^53` to `2^53 - 1` for some
operations, but if we generate WebAssembly some day, we would do the traditional
The safe range starts from -(2^53 - 1) and not from -2^53.
This is mentioned e.g. at MDN:
The Number.MIN_SAFE_INTEGER constant represents
the minimum safe integer in JavaScript (-(2^53 - 1)).