Syntax error on numeric literal suffixes in `defaults`

[Stranger6667]

Description

When a Rust function has multiple arguments and one of them is of the usize type, and the provided default value for this argument uses the _usize suffix, it leads to a syntax error on the PHP side when that other arguments is passed but the usize one is omitted.

Steps to Reproduce

1. Update tests/src/integration/defaults/defaults.php with the PHP sample below
2. Update tests/src/integration/defaults/mod.rs with the extension code below
3. Run cargo test --release --all integration::defaults::tests::defaults_works

Example

Extension Code:

#[php_function]
#[php(defaults(a = 42_usize, b = None))]
pub fn test_defaults_with_numeric_literal_type_suffix(
    a: usize,
    b: Option<String>,
) -> PhpResult<usize> {
    Ok(b.map(|b| b.len()).unwrap_or(a))
}


pub fn build_module(builder: ModuleBuilder) -> ModuleBuilder {
    builder
        .function(wrap_function!(test_defaults_with_numeric_literal_type_suffix))
}

PHP Code:

<?php

assert(test_defaults_with_numeric_literal_type_suffix() === 42);
assert(test_defaults_with_numeric_literal_type_suffix(5) === 5);
assert(test_defaults_with_numeric_literal_type_suffix(b: "b") === 1);
assert(test_defaults_with_numeric_literal_type_suffix(5, b: "b") === 1);

Actual Behavior

thread 'integration::defaults::tests::defaults_works' panicked at tests/src/integration/mod.rs:113:13:

                status: exit status: 255
                stdout:
                stderr: PHP Parse error:  syntax error, unexpected identifier "_usize" in  on line 1

Expected Behavior

The PHP snippet above should not fail

Log Output

Affected Components

• ext-php-rs
• macros
• cli (cargo-php)

PHP Version

PHP 8.4.10 (cli) (built: Jul  4 2025 12:41:44) (NTS)
Copyright (c) The PHP Group
Zend Engine v4.4.10, Copyright (c) Zend Technologies

ext-php-rs Version

0.14.1

Operating System

No response