runtime: Remove now unnecessary pad field from ParFor.

It is not needed due to the removal of the ctx field.
    
    Reviewed-on: https://go-review.googlesource.com/16525

From-SVN: r229616

libgo/go/net/hosts.go

@@ -2,8 +2,6 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-// Read static host/IP entries from /etc/hosts.
-
 package net
 
 import (
@@ -13,8 +11,21 @@ import (
 
 const cacheMaxAge = 5 * time.Minute
 
-// hostsPath points to the file with static IP/address entries.
-var hostsPath = "/etc/hosts"
+func parseLiteralIP(addr string) string {
+	var ip IP
+	var zone string
+	ip = parseIPv4(addr)
+	if ip == nil {
+		ip, zone = parseIPv6(addr, true)
+	}
+	if ip == nil {
+		return ""
+	}
+	if zone == "" {
+		return ip.String()
+	}
+	return ip.String() + "%" + zone
+}
 
 // Simple cache.
 var hosts struct {
@@ -27,7 +38,7 @@ var hosts struct {
 
 func readHosts() {
 	now := time.Now()
-	hp := hostsPath
+	hp := testHookHostsPath
 	if len(hosts.byName) == 0 || now.After(hosts.expire) || hosts.path != hp {
 		hs := make(map[string][]string)
 		is := make(map[string][]string)
@@ -41,13 +52,17 @@ func readHosts() {
 				line = line[0:i]
 			}
 			f := getFields(line)
-			if len(f) < 2 || ParseIP(f[0]) == nil {
+			if len(f) < 2 {
+				continue
+			}
+			addr := parseLiteralIP(f[0])
+			if addr == "" {
 				continue
 			}
 			for i := 1; i < len(f); i++ {
 				h := f[i]
-				hs[h] = append(hs[h], f[0])
-				is[f[0]] = append(is[f[0]], h)
+				hs[h] = append(hs[h], addr)
+				is[addr] = append(is[addr], h)
 			}
 		}
 		// Update the data cache.
@@ -77,6 +92,10 @@ func lookupStaticAddr(addr string) []string {
 	hosts.Lock()
 	defer hosts.Unlock()
 	readHosts()
+	addr = parseLiteralIP(addr)
+	if addr == "" {
+		return nil
+	}
 	if len(hosts.byAddr) != 0 {
 		if hosts, ok := hosts.byAddr[addr]; ok {
 			return hosts