A bool payload beside a bool literal never matches in an incomplete match #9035

In an untagged variant with a bool literal and a bool payload, a match that doesn't name every case sends values to the wrong arm:

@unboxed type t = | @as(true) LitTrue | AnyBool(bool) | AnyInt(int)
let f = (v: t) =>
  switch v {
  | AnyBool(_) => "bool"
  | _ => "other"
  }
Console.log([LitTrue, AnyBool(false), AnyInt(1)]->Array.map(f))

function f(v) {
  return "other";
}

f(AnyBool(false)) returns "other", but should return "bool". With @as(false) instead of @as(true), every value goes to the AnyBool arm.

Observed on master (d48d577). Cause: Js_exp_make.simplify_and_ rewrites typeof x === "boolean" && x !== b to the constant !b. Its doc comment says the result is x === !b, which is what's correct. The match produces exactly this conjunction for a bool payload beside a bool literal.

Found by a review of the untagged variant work (#8950).