Fix meta variable misuse

[ia0]

Rust issue: rust-lang/rust#61053
Rust PR: rust-lang/rust#62008

Reproduce by compiling with a stage2 (or stage1) compiler at the PR given above (set the meta_variable_misuse lint to deny if it's not). The output would look like (only first errors are kept):

error: unknown macro variable `submac2`
   --> src/combinator/macros.rs:660:41
    |
660 |     $crate::combinator::verify($f, |&o| $submac2!(o, $($args)*))($i)
    |                                         ^^^^^^^^
    |
    = note: #[deny(meta_variable_misuse)] on by default

error: meta-variable repeats with different Kleene operator
   --> src/branch/mod.rs:215:75
    |
199 |   ($it:tt, $self:expr, $input:ident, $res:expr, $all_done:expr, $head:ident $($id:ident)+) => ({
    |                                                                                         - expected repetition
...
215 |     succ!($it, permutation_trait_inner!($self, $input, $res, $all_done, $($id)*));
    |                                                                           ^^^ - conflicting repetition

error: unknown macro variable `args`
   --> src/sequence/macros.rs:471:43
    |
471 |   (( $(args:tt)* )) => ( compile_error!($($args)*) );
    |                                           ^^^^^

error: meta-variable repeats with different Kleene operator
   --> src/whitespace.rs:147:67
    |
144 |   ($i:expr, $separator:path, $submac1:ident!( $($args1:tt)* ), $($rest:tt)+) => ({
    |                                                                           - expected repetition
...
147 |     match tuple_sep!($i, $separator, (), $submac1!($($args1)*), $($rest)*) {
    |                                                                   ^^^^^ - conflicting repetition

[Geal]

wow that PR will really make things easier :)