all: update references to symbols moved from os to io/fs

The old os references are still valid, but update our code
to reflect best practices and get used to the new locations.

Code compiled with the bootstrap toolchain
(cmd/asm, cmd/dist, cmd/compile, debug/elf)
must remain Go 1.4-compatible and is excluded.

For #41190.

Change-Id: I8f9526977867c10a221e2f392f78d7dec073f1bd
Reviewed-on: https://go-review.googlesource.com/c/go/+/243907
Trust: Russ Cox <rsc@golang.org>
Run-TryBot: Russ Cox <rsc@golang.org>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Rob Pike <r@golang.org>

2 files changed, 5 insertions, 3 deletions

diff --git a/src/io/ioutil/ioutil.go b/src/io/ioutil/ioutil.go
index acc6ec3a40..cae41f0018 100644
--- a/src/io/ioutil/ioutil.go
+++ b/src/io/ioutil/ioutil.go
@@ -8,6 +8,7 @@ package ioutil
 import (
 	"bytes"
 	"io"
+	"io/fs"
 	"os"
 	"sort"
 	"sync"
@@ -76,7 +77,7 @@ func ReadFile(filename string) ([]byte, error) {
 // WriteFile writes data to a file named by filename.
 // If the file does not exist, WriteFile creates it with permissions perm
 // (before umask); otherwise WriteFile truncates it before writing, without changing permissions.
-func WriteFile(filename string, data []byte, perm os.FileMode) error {
+func WriteFile(filename string, data []byte, perm fs.FileMode) error {
 	f, err := os.OpenFile(filename, os.O_WRONLY|os.O_CREATE|os.O_TRUNC, perm)
 	if err != nil {
 		return err
@@ -90,7 +91,7 @@ func WriteFile(filename string, data []byte, perm os.FileMode) error {
 
 // ReadDir reads the directory named by dirname and returns
 // a list of directory entries sorted by filename.
-func ReadDir(dirname string) ([]os.FileInfo, error) {
+func ReadDir(dirname string) ([]fs.FileInfo, error) {
 	f, err := os.Open(dirname)
 	if err != nil {
 		return nil, err
diff --git a/src/io/ioutil/tempfile_test.go b/src/io/ioutil/tempfile_test.go
index fcc5101fcc..440c7cffc6 100644
--- a/src/io/ioutil/tempfile_test.go
+++ b/src/io/ioutil/tempfile_test.go
@@ -5,6 +5,7 @@
 package ioutil_test
 
 import (
+	"io/fs"
 	. "io/ioutil"
 	"os"
 	"path/filepath"
@@ -151,7 +152,7 @@ func TestTempDir_BadDir(t *testing.T) {
 
 	badDir := filepath.Join(dir, "not-exist")
 	_, err = TempDir(badDir, "foo")
-	if pe, ok := err.(*os.PathError); !ok || !os.IsNotExist(err) || pe.Path != badDir {
+	if pe, ok := err.(*fs.PathError); !ok || !os.IsNotExist(err) || pe.Path != badDir {
 		t.Errorf("TempDir error = %#v; want PathError for path %q satisifying os.IsNotExist", err, badDir)
 	}
 }