ZPP: Return tristate from zend_parse_arg_bool_weak()

[Girgias]

Follow-up PR on top of #21737.

This idea is based on @ndossche previous PR to reduce codebloat: #18436

This effectively allows us to return the boolean value via the return type rather than using an out pointer.

[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	2026-04-12 15:10:23 UTC
Job details	https://github.com/php/php-src/actions/runs/24309681555 (Artifacts)
Changeset	https://github.com/php/php-src/compare/361084086d..90efcd9280

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@3610840	0.39034	0.39227	0.00033	0.08%	0.39077	0.00%	0.39072	0.00%	2.089	0.000	1.000	24.85 MB
PHP - zpp-bool-direct-return	0.38813	0.38966	0.00033	0.09%	0.38864	-0.54%	0.38854	-0.56%	1.274	8.614	0.000	24.91 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@3610840	0.67051	0.67594	0.00091	0.14%	0.67157	0.00%	0.67136	0.00%	3.005	0.000	1.000	25.25 MB
PHP - zpp-bool-direct-return	0.66579	0.66812	0.00044	0.07%	0.66638	-0.77%	0.66626	-0.76%	1.692	8.614	0.000	25.18 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@3610840	0.58620	0.58970	0.00066	0.11%	0.58695	0.00%	0.58674	0.00%	2.661	0.000	1.000	25.27 MB
PHP - zpp-bool-direct-return	0.58573	0.58917	0.00077	0.13%	0.58674	-0.04%	0.58657	-0.03%	1.349	2.516	0.012	25.15 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@3610840	0.44470	0.44698	0.00043	0.10%	0.44589	0.00%	0.44588	0.00%	-0.262	0.000	1.000	25.27 MB
PHP - zpp-bool-direct-return	0.44513	0.44745	0.00049	0.11%	0.44603	0.03%	0.44607	0.04%	0.572	-1.224	0.221	25.15 MB