Empty {} in string interpolation should fail

[JohnnyMorganz]

#253

local _ = `asdf{}`

This currently passes, but it should fail.
Luau errors with "SyntaxError: Malformed interpolated string, expected expression inside '{}"

[jeparlefrancais]

I don't know if it's preferable to create another issue but I also noticed that the string { {} } does not parse in full-moon in the latest version:

unexpected double brace for interpolated string. try \\{ if you meant to escape

But if you give it a try on https://luau-lang.org/demo, it does work:

[Kampfkarren]

That actually probably shouldn't work in Luau either... :P

But c'est la vie

[jeparlefrancais]

Yeah I don't know where I sit with if it should or shouldn't, but I do believe it's a little confusing to work with because it's very hard to predict this:

local _ = `{{ }}` -- err
local _ = `{ {}}` -- ok
local _ = `{--[[]]{}}` -- ok
local _ = `\{{true}` -- ok
local _ = `{{hello}}` -- err
local _ = `{ {hello}}` -- ok
local _ = `\{{hello}}` -- ok

😕