Also use zval_get_double for op1 in pow comp time check

Mostly for consistency, but this will also allow evaluating more expressions at
compile time.

Author: iluuu1994

Zend/zend_compile.c

@@ -8992,7 +8992,7 @@ ZEND_API bool zend_binary_op_produces_error(uint32_t opcode, const zval *op1, co
 		/* Division by zero throws an error. */
 		return 1;
 	}
-	if ((opcode == ZEND_POW) && zval_get_long(op1) == 0 && zval_get_double(op2) < 0) {
+	if ((opcode == ZEND_POW) && zval_get_double(op1) == 0 && zval_get_double(op2) < 0) {
 		/* 0 ** (<0) throws a division by zero error. */
 		return 1;
 	}