Description:
------------
This is a problem related to cast_object handlers for internal classes.

When using an object with a cast handler in arithmetic, integer conversion is triggered instead of floating point conversion, even in situations where floating point math is used.

The expected behavior would be that the floating point cast is triggered instead.

If only a cast handler for floating point is present, the conversion even fails outright with the message that the object could not be converted to an integer. The cast to double isn't even attempted.

This may be related to #54973.

Test script:
---------------
The entire extension can be found at https://github.com/hartenfels/castbug

static int castbug_cast(zval *readobj, zval *retval, int type TSRMLS_DC)
{
    if (type == IS_LONG) {
        ZVAL_LONG(retval, 123);
        return SUCCESS;
    }
    else if (type == IS_DOUBLE) {
        ZVAL_DOUBLE(retval, 31.41);
        return SUCCESS;
    }
    else {
        return FAILURE;
    }
}

<?php
$cb = new CastBug();

/* these work as expected */
var_dump((int) $cb);
var_dump((float) $cb);

/* these use integer conversion instead of double conversion */
var_dump($cb + 1.5);
var_dump($cb * 2.0);
var_dump($cb / 10.0);

Expected result:
----------------
int(123)
float(31.41)
float(32.91)
float(62.82)
float(3.141)

Actual result:
--------------
int(123)
float(31.41)
float(124.5)
float(246)
float(12.3)