Constant idna::uts46::PUNYCODE_ENCODE_MAX_INPUT_LENGTH

const PUNYCODE_ENCODE_MAX_INPUT_LENGTH: usize = 1000;

ICU4C-compatible constraint. (Note: ICU4C measures UTF-16 and we measure UTF-32. This means that we allow longer non-BMP inputs. For this implementation, the denial-of-service scaling does not depend on BMP vs. non-BMP: only the scalar values matter.)

https://unicode-org.atlassian.net/browse/ICU-13727