[std] Fixed bug missing optional for lpName param on CreateEventExW. fixes #19946

https://learn.microsoft.com/en-us/windows/win32/api/synchapi/nf-synchapi-createeventexw

Author: Pyrolistical

lib/std/os/windows.zig

@@ -304,7 +304,7 @@ pub fn CreateEventEx(attributes: ?*SECURITY_ATTRIBUTES, name: []const u8, flags:
     return CreateEventExW(attributes, nameW.span().ptr, flags, desired_access);
 }
 
-pub fn CreateEventExW(attributes: ?*SECURITY_ATTRIBUTES, nameW: [*:0]const u16, flags: DWORD, desired_access: DWORD) !HANDLE {
+pub fn CreateEventExW(attributes: ?*SECURITY_ATTRIBUTES, nameW: ?LPCWSTR, flags: DWORD, desired_access: DWORD) !HANDLE {
     const handle = kernel32.CreateEventExW(attributes, nameW, flags, desired_access);
     if (handle) |h| {
         return h;

lib/std/os/windows/kernel32.zig

@@ -82,7 +82,7 @@ pub extern "kernel32" fn SetEndOfFile(hFile: HANDLE) callconv(WINAPI) BOOL;
 
 pub extern "kernel32" fn CreateEventExW(
     lpEventAttributes: ?*SECURITY_ATTRIBUTES,
-    lpName: [*:0]const u16,
+    lpName: ?LPCWSTR,
     dwFlags: DWORD,
     dwDesiredAccess: DWORD,
 ) callconv(WINAPI) ?HANDLE;