syscall: rewrite handle inheritance test to use C rather than Powershell

In CL 327210, we disabled this test on arm platforms, because the
powershell shipped with those systems isn't native, which means it'd
refuse to load native DLLs. This commit rewrites the test to simply not
use Powershell, and instead compiles a trivial C program that tests for
the same thing. Reverting CL 316269 makes this test fail, as desired,
while applying it makes this test succeed.

Fixes #46701

Change-Id: If39612c57bf74c63adf58e2c49b5cb739b461fe5
Reviewed-on: https://go-review.googlesource.com/c/go/+/327969
Trust: Jason A. Donenfeld <Jason@zx2c4.com>
Trust: Alex Brainman <alex.brainman@gmail.com>
Run-TryBot: Jason A. Donenfeld <Jason@zx2c4.com>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Alex Brainman <alex.brainman@gmail.com>

src/syscall/syscall_windows_test.go

@@ -10,7 +10,6 @@ import (
 	"os"
 	"os/exec"
 	"path/filepath"
-	"runtime"
 	"strings"
 	"syscall"
 	"testing"
@@ -80,9 +79,6 @@ func TestTOKEN_ALL_ACCESS(t *testing.T) {
 func TestStdioAreInheritable(t *testing.T) {
 	testenv.MustHaveGoBuild(t)
 	testenv.MustHaveExecPath(t, "gcc")
-	if runtime.GOARCH == "arm64" || runtime.GOARCH == "arm" {
-		t.Skip("Powershell is not native on ARM; see golang.org/issues/46701")
-	}
 
 	tmpdir := t.TempDir()
 
@@ -114,18 +110,28 @@ func main() {}
 		t.Fatalf("failed to build go library: %s\n%s", err, out)
 	}
 
-	// run powershell script
-	psscript := fmt.Sprintf(`
-hostname;
-$signature = " [DllImport("%q")] public static extern void HelloWorld(); ";
-Add-Type -MemberDefinition $signature -Name World -Namespace Hello;
-[Hello.World]::HelloWorld();
-hostname;
-`, dll)
-	psscript = strings.ReplaceAll(psscript, "\n", "")
-	out, err = exec.Command("powershell", "-Command", psscript).CombinedOutput()
+	// build c exe
+	const exetext = `
+#include <stdlib.h>
+#include <windows.h>
+int main(int argc, char *argv[])
+{
+	system("hostname");
+	((void(*)(void))GetProcAddress(LoadLibraryA(%q), "HelloWorld"))();
+	system("hostname");
+	return 0;
+}
+`
+	exe := filepath.Join(tmpdir, "helloworld.exe")
+	cmd = exec.Command("gcc", "-o", exe, "-xc", "-")
+	cmd.Stdin = strings.NewReader(fmt.Sprintf(exetext, dll))
+	out, err = testenv.CleanCmdEnv(cmd).CombinedOutput()
+	if err != nil {
+		t.Fatalf("failed to build c executable: %s\n%s", err, out)
+	}
+	out, err = exec.Command(exe).CombinedOutput()
 	if err != nil {
-		t.Fatalf("Powershell command failed: %v: %v", err, string(out))
+		t.Fatalf("c program execution failed: %v: %v", err, string(out))
 	}
 
 	hostname, err := os.Hostname()
@@ -137,6 +143,6 @@ hostname;
 	have = strings.ReplaceAll(have, "\r", "")
 	want := fmt.Sprintf("%sHello World%s", hostname, hostname)
 	if have != want {
-		t.Fatalf("Powershell command output is wrong: got %q, want %q", have, want)
+		t.Fatalf("c program output is wrong: got %q, want %q", have, want)
 	}
 }