Provide the method to retrieve why the system call has been failed.

[bupjae]

Source code:

package main

import (
	"fmt"
	"github.com/lxn/win"
	"golang.org/x/sys/windows"
)

func main() {
	wrongName := windows.StringToUTF16Ptr("ADFADFASDFSDAFASFD")
	handle := win.GetModuleHandle(wrongName)
	if handle == 0 {
		fmt.Println(win.GetLastError()) // This always returns 0. See https://github.com/golang/go/issues/41220
	}
}

Expected result:
Error code describing 'module not found' (ERROR_MOD_NOT_FOUND, 126)

Actual result:
0

According to golang/go#41220 , windows.GetLastError always returns nil. As the same reason, win.GetLastError always returns 0.

As wrapper provided by this package doesn't handle err return value from syscall.Syscall, the client doesn't know why the function call was failed.