Optimize false === is_string($x) in opcache

[TysonAndre]

This optimization acts on opcodes that are guaranteed to return booleans.
(It's based on the below case for ZEND_BOOL and ZEND_BOOL_NOT)
Code such as return is_string($this->prop) === false; will benefit from it when
opcache is enabled.

A contrived example of a worst-case scenario is below.

// Before this PR: Took 0.459 seconds
// After this PR: Takes 0.362 seconds
loop_is_float(0, 20000000);
function loop_is_float($a, $b) {
  $values = [];
  for ($i = $a; $i < $b; $i++) {
      $values[false === is_float($i)] = true;
  }
  return $values;
}

This PR uses bit operations,
so that this optimization will also work for false !== is_string($x)
and any future combinations generated for ZEND_TYPE_CHECK.

Similar to GH-4906 (can be merged independently)

EDIT: Fixed, that should have been a logical xor, not a binary xor

[TysonAndre]

The build is passing - the only issue in php.php-src was the runner for MacOS getting cancelled.

[ramsey]

This needs a review, please! If approved, I'd like to get it merge to master for 8.2.