Found in #5676 (comment)

Failed regexp is /\0003/.

This is parsed as:

• Character(Octal): \000
• Character(Symbol): 3

But once to_stringed, this will be /\03/.

This is parsed as:

• Character(Octal): \03

Because we remove leading 0s for now.

This also happens:

• /\0111/ => /\111/
• /\0022/ => /\22/

Is it possible to restore these without having extra raw field in the AST?

But both \000 and \00 are the same Character(Octal)...