Implement optimization to cast values instead of verifying the type

[Girgias]

I came up with this idea while working on #21580, but no idea if this is a safe way to write an optimization clearly not because it seems to segfault everything.

[ndossche]

It doesn't work because you need a result var. Furthermore the op handler destroys OP1 after setting the result, so they can't use the same TMP

[Girgias]

Attempting a new approach suggested by Arnaud to instead use VM specializations.

I might revert the string one and just have a generic one as it's getting kinda complicated...

[github-actions]

AWS x86_64 (c6id.metal)

Attribute	Value
Environment	aws
Instance type	c6id.metal
Architecture	x86_64
CPU	Intel(R) Xeon(R) Platinum 8375C CPU @ 2.90GHz, 64 cores @ 2900 MHz
CPU settings	disabled deeper C-states, disabled turbo boost, disabled hyper-threading
RAM	251 GB
Kernel	6.12.66-88.122.amzn2023.x86_64
OS	Amazon Linux 2023.10.20260202
GCC	14.2.1
Time	2026-04-10 19:50:47 UTC
Job details	https://github.com/php/php-src/actions/runs/24261213322 (Artifacts)
Changeset	https://github.com/php/php-src/compare/663efacb91..6cf5401ad9

Laravel 12.11.0 demo app - 50 iterations, 50 warmups, 100 requests (sec)

PHP	Min	Max	Std dev	Rel std dev %	Mean	Mean diff %	Median	Median diff %	Skewness	Z-stat	P-value	Memory
PHP - baseline@663efac	0.38778	0.38910	0.00029	0.07%	0.38829	0.00%	0.38828	0.00%	0.878	0.000	1.000	25.31 MB
PHP - optimize-zend-verify-return-type	0.38489	0.38784	0.00045	0.12%	0.38554	-0.71%	0.38546	-0.73%	3.095	8.600	0.000	25.29 MB

Symfony 2.8.0 demo app - 50 iterations, 50 warmups, 100 requests (sec)

PHP	Min	Max	Std dev	Rel std dev %	Mean	Mean diff %	Median	Median diff %	Skewness	Z-stat	P-value	Memory
PHP - baseline@663efac	0.66269	0.66406	0.00032	0.05%	0.66311	0.00%	0.66306	0.00%	1.375	0.000	1.000	25.26 MB
PHP - optimize-zend-verify-return-type	0.65845	0.66408	0.00103	0.16%	0.65922	-0.59%	0.65883	-0.64%	3.019	8.269	0.000	25.25 MB

Wordpress 6.9 main page - 50 iterations, 20 warmups, 20 requests (sec)

PHP	Min	Max	Std dev	Rel std dev %	Mean	Mean diff %	Median	Median diff %	Skewness	Z-stat	P-value	Memory
PHP - baseline@663efac	0.58456	0.58881	0.00084	0.14%	0.58540	0.00%	0.58514	0.00%	2.474	0.000	1.000	25.22 MB
PHP - optimize-zend-verify-return-type	0.58409	0.58678	0.00062	0.11%	0.58479	-0.10%	0.58457	-0.10%	1.729	5.325	0.000	25.27 MB

bench.php - 50 iterations, 20 warmups, 2 requests (sec)

PHP	Min	Max	Std dev	Rel std dev %	Mean	Mean diff %	Median	Median diff %	Skewness	Z-stat	P-value	Memory
PHP - baseline@663efac	0.44436	0.44656	0.00048	0.11%	0.44562	0.00%	0.44560	0.00%	-0.195	0.000	1.000	25.22 MB
PHP - optimize-zend-verify-return-type	0.44679	0.44952	0.00050	0.11%	0.44787	0.51%	0.44782	0.50%	0.668	-8.614	0.000	25.27 MB