Add a Broadcast property to HWND for clearer semantics

[vitkuz573]

I've been working with the HWND structure and realized that it might be beneficial to have a Broadcast property directly in the HWND structure to represent the broadcast handle, rather than casting it manually each time using (HWND)0xFFFF.

Proposal:
Add a static property to HWND that represents the broadcast handle. This would make the code more readable and reduce the potential for errors.

public static HWND Broadcast => new HWND(0xFFFF);

[elachlan]

What projection are you using? That is usually done in those.

[vitkuz573]

I'm using CsWin32

[elachlan]

https://learn.microsoft.com/en-us/windows/win32/api/winuser/nf-winuser-sendmessage

I guess we should add a new const in the metadata HWND_BROADCAST ((HWND)0xffff) similar to HWND_TOP and the others.

[elachlan]

It exists in the headers:

win32metadata/generation/WinSDK/RecompiledIdlHeaders/um/WinUser.h

Lines 4079 to 4082 in 581c639

	/*
	* Special HWND value for use with PostMessage() and SendMessage()
	*/
	#define HWND_BROADCAST ((HWND)0xffff)

[elachlan]

The ConstantsScraper does not handle the value 0xffff, if I replace the value in the header with 65535 it gets picked up.