libgo: update to Go1.18beta2

gotools/
	* Makefile.am (go_cmd_cgo_files): Add ast_go118.go
	(check-go-tool): Copy golang.org/x/tools directories.
	* Makefile.in: Regenerate.

Reviewed-on: https://go-review.googlesource.com/c/gofrontend/+/384695

1 files changed, 13 insertions, 3 deletions

diff --git a/libgo/go/embed/embed.go b/libgo/go/embed/embed.go
index 851cc21..9737ccd 100644
--- a/libgo/go/embed/embed.go
+++ b/libgo/go/embed/embed.go
@@ -80,11 +80,15 @@
 //	var content embed.FS
 //
 // The difference is that ‘image/*’ embeds ‘image/.tempfile’ while ‘image’ does not.
+// Neither embeds ‘image/dir/.tempfile’.
+//
+// If a pattern begins with the prefix ‘all:’, then the rule for walking directories is changed
+// to include those files beginning with ‘.’ or ‘_’. For example, ‘all:image’ embeds
+// both ‘image/.tempfile’ and ‘image/dir/.tempfile’.
 //
 // The //go:embed directive can be used with both exported and unexported variables,
 // depending on whether the package wants to make the data available to other packages.
-// It can only be used with global variables at package scope,
-// not with local variables.
+// It can only be used with variables at package scope, not with local variables.
 //
 // Patterns must not match files outside the package's module, such as ‘.git/*’ or symbolic links.
 // Matches for empty directories are ignored. After that, each pattern in a //go:embed line
@@ -228,7 +232,7 @@ func (f *file) Name() string               { _, elem, _ := split(f.name); return
 func (f *file) Size() int64                { return int64(len(f.data)) }
 func (f *file) ModTime() time.Time         { return time.Time{} }
 func (f *file) IsDir() bool                { _, _, isDir := split(f.name); return isDir }
-func (f *file) Sys() interface{}           { return nil }
+func (f *file) Sys() any                   { return nil }
 func (f *file) Type() fs.FileMode          { return f.Mode().Type() }
 func (f *file) Info() (fs.FileInfo, error) { return f, nil }
 
@@ -292,6 +296,8 @@ func (f FS) readDir(dir string) []file {
 }
 
 // Open opens the named file for reading and returns it as an fs.File.
+//
+// The returned file implements io.Seeker when the file is not a directory.
 func (f FS) Open(name string) (fs.File, error) {
 	file := f.lookup(name)
 	if file == nil {
@@ -339,6 +345,10 @@ type openFile struct {
 	offset int64 // current read offset
 }
 
+var (
+	_ io.Seeker = (*openFile)(nil)
+)
+
 func (f *openFile) Close() error               { return nil }
 func (f *openFile) Stat() (fs.FileInfo, error) { return f.f, nil }