[bug] incorrect return type annotation for Stdlib_RegExp.Result.matches

[tx46]

  @send external matches: (t, @as(1) _) => array<string> = "slice"

This has the return type array<string>, but it should likely be array<option<string>>. Minimal repro:

let foo ="x"
let re = %re("/(y)?(z)?/")

switch foo->String.match(re) {
  | Some(m) =>
  let matches = m->RegExp.Result.matches
  switch matches {
    | [a, b] =>
    Console.log2(a, b)
    Console.log(matches)
  }
}

Output:

undefined undefined

[null,null]

If array<string> was correct, output should be ["", ""]. Replace Console.log2(a, b) with the following for runtime breakage:

    Console.log(a->String.length)

[mediremi]

This is fixed in v12.0.0-alpha.12+ btw: rescript-lang/rescript#7393

[zth]

As noted above, this should be fixed. Please feel free to reopen if you discover it's not.