Add support for Bun JavaScript Runtime

[Whobeu]

I have been experimenting with the new Bun JavaScript runtime and have found that yargs does not understand this new runtime. When referencing the $0 variable in yargs, it return "bun" instead of the script being run. As a quick hack, I modified index.cjs to include "bun" to the Regex statement:

/\b(node|iojs|electron)(\.exe)?$/

which becomes

/\b(node|iojs|electron|bun)(\.exe)?$/

This works and $0 now correctly reflects the script being executed. I would propose that a single line in yargs-factory.js be changed to the following so that index.cjs is updated with the new check:

if (/\b(node|iojs|electron|bun)(\.exe)?$/.test(__classPrivateFieldGet(this, _YargsInstance_shim, "f").process.argv()[0])) {

[shadowspawn]

I have not tested it, but the change is consistent with the existing code. 👍

yargs/lib/yargs-factory.ts

Line 1548 in e517318

if (/\b(node|iojs|electron)(\.exe)?$/.test(this.#shim.process.argv()[0])) {

[bcoe]

_@Whobeu drive by comment 😛 _

Create a patch and we can land.