libgo: update to Go1.12beta2

    
    Reviewed-on: https://go-review.googlesource.com/c/158019

gotools/:
	* Makefile.am (go_cmd_vet_files): Update for Go1.12beta2 release.
	(GOTOOLS_TEST_TIMEOUT): Increase to 600.
	(check-runtime): Export LD_LIBRARY_PATH before computing GOARCH
	and GOOS.
	(check-vet): Copy golang.org/x/tools into check-vet-dir.
	* Makefile.in: Regenerate.

gcc/testsuite/:
	* go.go-torture/execute/names-1.go: Stop using debug/xcoff, which
	is no longer externally visible.

From-SVN: r268084

5 files changed, 71 insertions, 17 deletions

diff --git a/libgo/go/strconv/atoi.go b/libgo/go/strconv/atoi.go
index bebed04..ff33d55 100644
--- a/libgo/go/strconv/atoi.go
+++ b/libgo/go/strconv/atoi.go
@@ -44,7 +44,7 @@ const intSize = 32 << (^uint(0) >> 63)
 // IntSize is the size in bits of an int or uint value.
 const IntSize = intSize
 
-const maxUint64 = (1<<64 - 1)
+const maxUint64 = 1<<64 - 1
 
 // ParseUint is like ParseInt but for unsigned numbers.
 func ParseUint(s string, base int, bitSize int) (uint64, error) {
@@ -198,7 +198,7 @@ func ParseInt(s string, base int, bitSize int) (i int64, err error) {
 	return n, nil
 }
 
-// Atoi returns the result of ParseInt(s, 10, 0) converted to type int.
+// Atoi is equivalent to ParseInt(s, 10, 0), converted to type int.
 func Atoi(s string) (int, error) {
 	const fnAtoi = "Atoi"
 
diff --git a/libgo/go/strconv/doc.go b/libgo/go/strconv/doc.go
index cba8984..8db725f 100644
--- a/libgo/go/strconv/doc.go
+++ b/libgo/go/strconv/doc.go
@@ -46,8 +46,8 @@
 // The latter guarantees that the result is an ASCII string, by escaping
 // any non-ASCII Unicode with \u:
 //
-//	q := Quote("Hello, 世界")
-//	q := QuoteToASCII("Hello, 世界")
+//	q := strconv.Quote("Hello, 世界")
+//	q := strconv.QuoteToASCII("Hello, 世界")
 //
 // QuoteRune and QuoteRuneToASCII are similar but accept runes and
 // return quoted Go rune literals.
diff --git a/libgo/go/strconv/example_test.go b/libgo/go/strconv/example_test.go
index 5c2e8a9..2d1a2a9 100644
--- a/libgo/go/strconv/example_test.go
+++ b/libgo/go/strconv/example_test.go
@@ -167,6 +167,22 @@ func ExampleFormatUint() {
 	// string, 2a
 }
 
+func ExampleIsGraphic() {
+	shamrock := strconv.IsGraphic('☘')
+	fmt.Println(shamrock)
+
+	a := strconv.IsGraphic('a')
+	fmt.Println(a)
+
+	bel := strconv.IsGraphic('\007')
+	fmt.Println(bel)
+
+	// Output:
+	// true
+	// true
+	// false
+}
+
 func ExampleIsPrint() {
 	c := strconv.IsPrint('\u263a')
 	fmt.Println(c)
@@ -249,7 +265,7 @@ func ExampleParseUint() {
 }
 
 func ExampleQuote() {
-	s := strconv.Quote(`"Fran & Freddie's Diner	☺"`)
+	s := strconv.Quote(`"Fran & Freddie's Diner	☺"`) // there is a tab character inside the string literal
 	fmt.Println(s)
 
 	// Output:
@@ -272,14 +288,50 @@ func ExampleQuoteRuneToASCII() {
 	// '\u263a'
 }
 
+func ExampleQuoteRuneToGraphic() {
+	s := strconv.QuoteRuneToGraphic('☺')
+	fmt.Println(s)
+
+	s = strconv.QuoteRuneToGraphic('\u263a')
+	fmt.Println(s)
+
+	s = strconv.QuoteRuneToGraphic('\u000a')
+	fmt.Println(s)
+
+	s = strconv.QuoteRuneToGraphic('	') // tab character
+	fmt.Println(s)
+
+	// Output:
+	// '☺'
+	// '☺'
+	// '\n'
+	// '\t'
+}
+
 func ExampleQuoteToASCII() {
-	s := strconv.QuoteToASCII(`"Fran & Freddie's Diner	☺"`)
+	s := strconv.QuoteToASCII(`"Fran & Freddie's Diner	☺"`) // there is a tab character inside the string literal
 	fmt.Println(s)
 
 	// Output:
 	// "\"Fran & Freddie's Diner\t\u263a\""
 }
 
+func ExampleQuoteToGraphic() {
+	s := strconv.QuoteToGraphic("☺")
+	fmt.Println(s)
+
+	s = strconv.QuoteToGraphic("This is a \u263a	\u000a") // there is a tab character inside the string literal
+	fmt.Println(s)
+
+	s = strconv.QuoteToGraphic(`" This is a ☺ \n "`)
+	fmt.Println(s)
+
+	// Output:
+	// "☺"
+	// "This is a ☺\t\n"
+	// "\" This is a ☺ \\n \""
+}
+
 func ExampleUnquote() {
 	s, err := strconv.Unquote("You can't unquote a string without quotes")
 	fmt.Printf("%q, %v\n", s, err)
diff --git a/libgo/go/strconv/itoa.go b/libgo/go/strconv/itoa.go
index 8afe7af..45e4192 100644
--- a/libgo/go/strconv/itoa.go
+++ b/libgo/go/strconv/itoa.go
@@ -30,7 +30,7 @@ func FormatInt(i int64, base int) string {
 	return s
 }
 
-// Itoa is shorthand for FormatInt(int64(i), 10).
+// Itoa is equivalent to FormatInt(int64(i), 10).
 func Itoa(i int) string {
 	return FormatInt(int64(i), 10)
 }
@@ -152,10 +152,14 @@ func formatBits(dst []byte, u uint64, base int, neg, append_ bool) (d []byte, s
 		}
 
 	} else if isPowerOfTwo(base) {
-		// It is known that base is a power of two and
-		// 2 <= base <= len(digits).
 		// Use shifts and masks instead of / and %.
-		shift := uint(bits.TrailingZeros(uint(base))) & 31
+		// Base is a power of 2 and 2 <= base <= len(digits) where len(digits) is 36.
+		// The largest power of 2 below or equal to 36 is 32, which is 1 << 5;
+		// i.e., the largest possible shift count is 5. By &-ind that value with
+		// the constant 7 we tell the compiler that the shift count is always
+		// less than 8 which is smaller than any register width. This allows
+		// the compiler to generate better code for the shift operation.
+		shift := uint(bits.TrailingZeros(uint(base))) & 7
 		b := uint64(base)
 		m := uint(base) - 1 // == 1<<shift - 1
 		for u >= b {
diff --git a/libgo/go/strconv/quote.go b/libgo/go/strconv/quote.go
index 9b7194a..6cd2f93 100644
--- a/libgo/go/strconv/quote.go
+++ b/libgo/go/strconv/quote.go
@@ -6,7 +6,10 @@
 
 package strconv
 
-import "unicode/utf8"
+import (
+	"internal/bytealg"
+	"unicode/utf8"
+)
 
 const lowerhex = "0123456789abcdef"
 
@@ -424,12 +427,7 @@ func Unquote(s string) (string, error) {
 
 // contains reports whether the string contains the byte c.
 func contains(s string, c byte) bool {
-	for i := 0; i < len(s); i++ {
-		if s[i] == c {
-			return true
-		}
-	}
-	return false
+	return bytealg.IndexByteString(s, c) != -1
 }
 
 // bsearch16 returns the smallest i such that a[i] >= x.