[PHP 8.4] Add bcdivmod

[alexandre-daubois]

Supersedes #503. Thank you @Ayesh!

[nicolas-grekas]

I changed the implementation this way:

• the validation of the arguments is already done by the call to bcdiv so there's not need to do it (and possibility introduce subtle behavioral diffs)
• the $scale of bcdiv should be 0explicitly IIUC

     public static function bcdivmod(string $num1, string $num2, ?int $scale = null): ?array
     {
-        if (PHP_FLOAT_EPSILON < abs((float) $num2)) {
-            throw new \DivisionByZeroError('Division by zero');
-        }
-
-        if (!is_numeric($num1)) {
-            if (class_exists(\ValueError::class)) {
-                throw new \ValueError('Argument #1 ($num1) is not well-formed');
-            }
-
-            trigger_error('Argument #1 ($num1) is not well-formed', E_USER_WARNING);
-
-            return null;
-        }
-
-        if (!is_numeric($num2)) {
-            if (class_exists(\ValueError::class)) {
-                throw new \ValueError('Argument #2 ($num2) is not well-formed');
-            }
-
-            trigger_error('Argument #2 ($num2) is not well-formed', E_USER_WARNING);
-
-            return null;
-        }
-
-        return [
-            \bcdiv($num1, $num2),
-            \bcmod($num1, $num2, $scale ?? \bcscale() ?? ini_get('bcmath.scale') ?: 0),
-        ];
+        if (null === $quot = \bcdiv($num1, $num2, 0)) {
+            return null;
+        }
+        $scale = $scale ?? (\PHP_VERSION_ID >= 70300 ? \bcscale() : (ini_get('bcmath.scale') ?: 0);
+
+        return [$quot, \bcmod($num1, $num2, $scale)];
     }

[nicolas-grekas]

Thank you @alexandre-daubois.

[nicolas-grekas]

And thank you @Ayesh !