feat(table): improve pretty-printing for simple tables and lists

[vhyrro]

Hi,

This PR improves the pretty printing code for Lua tables:

• Adds support for list rendering
• Adds support for rendering simple keys (["hello"] = 3) as just hello = 3

The use case for this is reading in a Lua file (like a rockspec), modifying its globals and then reconstructing the Lua file in a readable format. Given that debug pretty printing is for debugging (duh), I'm not classifying this as any sort of breaking change :)

One note: the is_sequence check goes through all keys in a table and checks if they're integers and in ascending order. The is_list() method is only for cfg!(serialize), so I've refrained from refactoring that in fear of breaking some obscure behaviour. Let me know if there's anything you'd change!

[vhyrro]

Saw that luau is failing, on it :)

edit: done! There's one test failure that's not caused by this pull request.

[khvzak]

Thanks

[khvzak]

I just noticed an edge case where tables like {["1"] = "first", ["2"] = "second"} will be wrongly formatted as:

{
  1 = "first",
  2 = "second",
}

This table cannot be loaded back to Lua.

Fixed in b34b90e

[vhyrro]

Oh good catch, sorry for that :)