Common empties microbenchmark

bench.js

console.time('new Set');
for (let i = 0; i < 1_000_000; i++) {
  new Set();
}
console.timeEnd('new Set');

console.time('new Map');
for (let i = 0; i < 1_000_000; i++) {
  new Map();
}
console.timeEnd('new Map');

console.time('[]');
for (let i = 0; i < 1_000_000; i++) {
  [];
}
console.timeEnd('[]');

console.time('() => {}');
for (let i = 0; i < 1_000_000; i++) {
  new Set();
}
console.timeEnd('() => {}');

console.time('(() => new Map)()');
for (let i = 0; i < 1_000_000; i++) {
  (() => new Map())();
}
console.timeEnd('(() => new Map)()');