libgo: update to Go1.16beta1 release

This does not yet include support for the //go:embed directive added
in this release.

	* Makefile.am (check-runtime): Don't create check-runtime-dir.
	(mostlyclean-local): Don't remove check-runtime-dir.
	(check-go-tool, check-vet): Copy in go.mod and modules.txt.
	(check-cgo-test, check-carchive-test): Add go.mod file.
	* Makefile.in: Regenerate.

Reviewed-on: https://go-review.googlesource.com/c/gofrontend/+/280172

2 files changed, 11 insertions, 5 deletions

diff --git a/libgo/go/bytes/example_test.go b/libgo/go/bytes/example_test.go
index 5ba7077..ae93202 100644
--- a/libgo/go/bytes/example_test.go
+++ b/libgo/go/bytes/example_test.go
@@ -30,6 +30,13 @@ func ExampleBuffer_reader() {
 	// Output: Gophers rule!
 }
 
+func ExampleBuffer_Bytes() {
+	buf := bytes.Buffer{}
+	buf.Write([]byte{'h', 'e', 'l', 'l', 'o', ' ', 'w', 'o', 'r', 'l', 'd'})
+	os.Stdout.Write(buf.Bytes())
+	// Output: hello world
+}
+
 func ExampleBuffer_Grow() {
 	var b bytes.Buffer
 	b.Grow(64)
diff --git a/libgo/go/bytes/reader_test.go b/libgo/go/bytes/reader_test.go
index d799e03..8baac50 100644
--- a/libgo/go/bytes/reader_test.go
+++ b/libgo/go/bytes/reader_test.go
@@ -8,7 +8,6 @@ import (
 	. "bytes"
 	"fmt"
 	"io"
-	"io/ioutil"
 	"sync"
 	"testing"
 )
@@ -235,7 +234,7 @@ func TestReaderCopyNothing(t *testing.T) {
 	type justWriter struct {
 		io.Writer
 	}
-	discard := justWriter{ioutil.Discard} // hide ReadFrom
+	discard := justWriter{io.Discard} // hide ReadFrom
 
 	var with, withOut nErr
 	with.n, with.err = io.Copy(discard, NewReader(nil))
@@ -248,7 +247,7 @@ func TestReaderCopyNothing(t *testing.T) {
 // tests that Len is affected by reads, but Size is not.
 func TestReaderLenSize(t *testing.T) {
 	r := NewReader([]byte("abc"))
-	io.CopyN(ioutil.Discard, r, 1)
+	io.CopyN(io.Discard, r, 1)
 	if r.Len() != 2 {
 		t.Errorf("Len = %d; want 2", r.Len())
 	}
@@ -268,7 +267,7 @@ func TestReaderReset(t *testing.T) {
 	if err := r.UnreadRune(); err == nil {
 		t.Errorf("UnreadRune: expected error, got nil")
 	}
-	buf, err := ioutil.ReadAll(r)
+	buf, err := io.ReadAll(r)
 	if err != nil {
 		t.Errorf("ReadAll: unexpected error: %v", err)
 	}
@@ -314,7 +313,7 @@ func TestReaderZero(t *testing.T) {
 		t.Errorf("UnreadRune: got nil, want error")
 	}
 
-	if n, err := (&Reader{}).WriteTo(ioutil.Discard); n != 0 || err != nil {
+	if n, err := (&Reader{}).WriteTo(io.Discard); n != 0 || err != nil {
 		t.Errorf("WriteTo: got %d, %v; want 0, nil", n, err)
 	}
 }