Add e2e tests

vendor/golang.org/x/sys/windows/syscall_test.go

@@ -7,6 +7,7 @@
 package windows_test
 
 import (
+	"syscall"
 	"testing"
 
 	"golang.org/x/sys/windows"
@@ -31,3 +32,22 @@ func TestEnv(t *testing.T) {
 	// make sure TESTENV gets set to "", not deleted
 	testSetGetenv(t, "TESTENV", "")
 }
+
+func TestGetProcAddressByOrdinal(t *testing.T) {
+	// Attempt calling shlwapi.dll:IsOS, resolving it by ordinal, as
+	// suggested in
+	// https://msdn.microsoft.com/en-us/library/windows/desktop/bb773795.aspx
+	h, err := windows.LoadLibrary("shlwapi.dll")
+	if err != nil {
+		t.Fatalf("Failed to load shlwapi.dll: %s", err)
+	}
+	procIsOS, err := windows.GetProcAddressByOrdinal(h, 437)
+	if err != nil {
+		t.Fatalf("Could not find shlwapi.dll:IsOS by ordinal: %s", err)
+	}
+	const OS_NT = 1
+	r, _, _ := syscall.Syscall(procIsOS, 1, OS_NT, 0, 0)
+	if r == 0 {
+		t.Error("shlwapi.dll:IsOS(OS_NT) returned 0, expected non-zero value")
+	}
+}