perf: cache intl object

[H4ad]

Inspired by https://twitter.com/jarredsumner/status/1749032292771942605

Before:

cpu: AMD Ryzen 9 5950X 16-Core Processor
runtime: node v20.7.0 (x64-linux)

benchmark                                    time (avg)             (min … max)       p75       p99      p995
------------------------------------------------------------------------------- -----------------------------
npm/string-width (ansi + emoji + ascii)   13.78 µs/iter     (11.2 µs … 1.24 ms)  11.74 µs  26.01 µs  28.73 µs
npm/string-width (ansi + emoji)            8.43 µs/iter      (8.09 µs … 9.2 µs)   8.65 µs    9.2 µs    9.2 µs
npm/string-width (ansi + ascii)           11.07 µs/iter     (9.27 µs … 3.05 ms)   9.87 µs  12.07 µs   13.8 µs

Now:

cpu: AMD Ryzen 9 5950X 16-Core Processor
runtime: node v20.7.0 (x64-linux)

benchmark                                    time (avg)             (min … max)       p75       p99      p995
------------------------------------------------------------------------------- -----------------------------
npm/string-width (ansi + emoji + ascii)    8.07 µs/iter   (7.08 µs … 397.88 µs)    7.4 µs   9.09 µs  11.83 µs
npm/string-width (ansi + emoji)            2.94 µs/iter     (2.82 µs … 3.34 µs)   2.99 µs   3.34 µs   3.34 µs
npm/string-width (ansi + ascii)            6.23 µs/iter     (6.18 µs … 6.32 µs)   6.24 µs   6.32 µs   6.32 µs

Benchmark:

import {bench, run} from 'mitata';
import npmStringWidth from './index.js';

bench('npm/string-width (ansi + emoji + ascii)', () => {
	npmStringWidth('hello there! 😀\u001B[31m😀😀');
});

bench('npm/string-width (ansi + emoji)', () => {
	npmStringWidth('😀\u001B[31m😀😀');
});

bench('npm/string-width (ansi + ascii)', () => {
	npmStringWidth('\u001B[31mhello there!');
});

run();