Functions which take Void as an argument cause the C++ compiler to error

```haxe
package;

class Main {
public static function main():Void {
var x:(Void)->Void = _ -> {
// bad function
}
}
}
```
Compiling this code gives an error from the C++ compiler:
```
$ haxe --cpp out Main.hx
haxelib run hxcpp Build.xml haxe -Dhaxe="4.3.7" -Dhaxe3="1" -Dhaxe4="1" -Dhaxe_ver="4.307" -Dhxcpp_api_level="430" -Dhxcpp_smart_strings="1" -Dsource_header="Generated by Haxe 4.3.7" -Dstatic="1" -Dtarget.atomics="1" -Dtarget.name="cpp" -Dtarget.static="1" -Dtarget.sys="1" -Dtarget.threaded="1" -Dtarget.unicode="1" -Dtarget.utf16="1" -Dutf16="1" -I -I/usr/share/haxe/std/cpp/_std/ -I/usr/share/haxe/std/
Creating /home/user/bug_report_hxcpp/out/obj/linux64/__pch/haxe/hxcpp.h.gch...

Compiling group: haxe
g++ -Iinclude -c -fvisibility=hidden -O2 -fpic -fPIC -Wno-overflow -DHX_LINUX -DHXCPP_M64 -DHXCPP_VISIT_ALLOCS(haxe) -DHX_SMART_STRINGS(haxe) -DHXCPP_API_LEVEL=430(haxe) -m64 -DHXCPP_M64 -I/home/user/haxe/hxcpp/4,3,2/include ... tags=[haxe,static]
- src/Main.cpp
Error: ./src/Main.cpp: In static member function ‘static void Main_obj::main()’:
./src/Main.cpp:29:43: error: invalid use of type ‘void’ in parameter declaration
29 | void _hx_run(void _){
| ~~~~~^
```
On other targets, this compiles without emitting an error.
I am using Linux, Haxe version 4.3.7, hxcpp version 4.3.2, and g++ version 15.1.1