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, 25 insertions, 0 deletions

diff --git a/libgo/go/unicode/utf8/utf8_test.go b/libgo/go/unicode/utf8/utf8_test.go
index eaf1b5ff..e9be4d2 100644
--- a/libgo/go/unicode/utf8/utf8_test.go
+++ b/libgo/go/unicode/utf8/utf8_test.go
@@ -127,6 +127,17 @@ func TestEncodeRune(t *testing.T) {
 	}
 }
 
+func TestAppendRune(t *testing.T) {
+	for _, m := range utf8map {
+		if buf := AppendRune(nil, m.r); string(buf) != m.str {
+			t.Errorf("AppendRune(nil, %#04x) = %s, want %s", m.r, buf, m.str)
+		}
+		if buf := AppendRune([]byte("init"), m.r); string(buf) != "init"+m.str {
+			t.Errorf("AppendRune(init, %#04x) = %s, want %s", m.r, buf, "init"+m.str)
+		}
+	}
+}
+
 func TestDecodeRune(t *testing.T) {
 	for _, m := range utf8map {
 		b := []byte(m.str)
@@ -583,6 +594,20 @@ func BenchmarkEncodeJapaneseRune(b *testing.B) {
 	}
 }
 
+func BenchmarkAppendASCIIRune(b *testing.B) {
+	buf := make([]byte, UTFMax)
+	for i := 0; i < b.N; i++ {
+		AppendRune(buf[:0], 'a')
+	}
+}
+
+func BenchmarkAppendJapaneseRune(b *testing.B) {
+	buf := make([]byte, UTFMax)
+	for i := 0; i < b.N; i++ {
+		AppendRune(buf[:0], '本')
+	}
+}
+
 func BenchmarkDecodeASCIIRune(b *testing.B) {
 	a := []byte{'a'}
 	for i := 0; i < b.N; i++ {