[Feature] Evaluated case elimination pass

function test(x: i32) : i32 {
  switch (x) {
    case 1: return 2;
    case 2: return 2;
  }
  return 2;
}

current with -O4:

  (func $test (export "test") (type $t0) (param $p0 i32) (result i32)
    block $B0
      block $B1
        get_local $p0
        i32.const 1
        i32.ne
        if $I2
          get_local $p0
          i32.const 2
          i32.eq
          br_if $B1
          br $B0
        end
        i32.const 2
        return
      end
      i32.const 2
      return
    end
    i32.const 2)

optimal (with evaluated case elimination transform):

(func $test (export "test") (type $t0) (param $p0 i32) (result i32)
   i32.const 2
)

Reproduce the example with -O4 and compare the current WebAssembly output with the optimal output shown in the issue. Locate the existing optimizer passes that simplify switch or evaluated cases, then verify that this example reduces to a function returning i32.const 2.