fix(wasix): Fix EFD_SEMAPHORE eventfd read value

[artemyarulin]

Fixes WASIX eventfd(EFD_SEMAPHORE) reads returning the full counter value instead of 1.

In semaphore mode, Linux eventfd semantics require each successful read to return 1 and decrement the counter by one. The WASIX notification counter was already decrementing one permit, but returned the pre-decrement counter, so reading after writing 4 returned 4.

Closes #6145

[artemyarulin]

Shield - Regression 💩💩💩

Language	Tests	Pass rate now	PASS	FAIL	TIMEOUT	CRASH
Python	37,920	68.8%	0	$${\color{red}+18}$$	$${\color{green}-19}$$	0
Node.js	4,861	32.7%	$${\color{green}+3}$$	$${\color{green}-51}$$	$${\color{red}+52}$$	$${\color{green}-1}$$
PHP	19,912	72.5%	$${\color{red}-1}$$	$${\color{red}+1}$$	0	0
Rust	22,337	94.3%	0	$${\color{green}-4}$$	0	0

More changed tests

• Python: tests_python_results.json
• Node.js: tests_node_results.json
• PHP: tests_php_results.json
• Rust: tests_rust_results.json

Install shield

• git clone https://github.com/wasmerio/compat-tests.git
• cd compat-tests
• cargo build
• ./target/debug/shield run --lang <LANG> --wasmer [WASMER BINARY] <TEST OR BATCH>

Artifacts

• GitHub Action: https://github.com/wasmerio/anti-regression-shield/actions/runs/25222485640
• Results commit: wasmerio/anti-regression-shield@45314a5

[marxin]

@artemyarulin Can we close the PR now as it was used just for testing?

[artemyarulin]

Sorry, it was used for testing, but it's an actual fix, so ready for the review

[marxin]

All right, so please port it to the new test harness, basically you just add the .c file and you are done.

EDITTED: done