Use the new arr[* - 1] syntax in a few places.
Allow ignored parameters in the form of #(, x) -> or #([, x]) -> Trailing ignored parameters are allowed, but completely ignored as well.
Allow ignored array elements in let array destructuring.
Add the special identifier GLOBAL, which will be set to window ? global ? this (the outermost this) if accessed somewhere within a file.
Add license comments, which are like regular multi-line comments but have the form /*! */. These are carried on to the resultant source code.
Allow $() calls as Identifiers if in an AST block.