stub out more types/funcs to compile against golang.org/x/net/internal/socket (#17)

* stub out more types/funcs to compile against golang.org/x/net/internal/socket

These are changes need to compile github.com/domainr/dnsr/ with TinyGo. See issue tinygo-org/net#14.

These change are mostly to fix missing symbols in src/net. Missing types and functions are cut-and-pasted from go1.21.4. Functions are stubbed out returning errors.New("not implemented").

DNRS is compiled by running tinygo test:

   sfeldma@nuc:~/work/dnsr$ tinygo test -target=wasi

With this patch, and a corresponding patch for tinygo/ to fixup crypto/tls, you should get a clean compile.

interface.go

@@ -0,0 +1,86 @@
+// TINYGO: The following is copied and modified from Go 1.21.4 official implementation.
+
+// Copyright 2011 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package net
+
+import (
+	"errors"
+)
+
+// BUG(mikio): On JS, methods and functions related to
+// Interface are not implemented.
+
+// BUG(mikio): On AIX, DragonFly BSD, NetBSD, OpenBSD, Plan 9 and
+// Solaris, the MulticastAddrs method of Interface is not implemented.
+
+var (
+	errInvalidInterface         = errors.New("invalid network interface")
+	errInvalidInterfaceIndex    = errors.New("invalid network interface index")
+	errInvalidInterfaceName     = errors.New("invalid network interface name")
+	errNoSuchInterface          = errors.New("no such network interface")
+	errNoSuchMulticastInterface = errors.New("no such multicast network interface")
+)
+
+// Interface represents a mapping between network interface name
+// and index. It also represents network interface facility
+// information.
+type Interface struct {
+	Index        int          // positive integer that starts at one, zero is never used
+	MTU          int          // maximum transmission unit
+	Name         string       // e.g., "en0", "lo0", "eth0.100"
+	HardwareAddr HardwareAddr // IEEE MAC-48, EUI-48 and EUI-64 form
+	Flags        Flags        // e.g., FlagUp, FlagLoopback, FlagMulticast
+}
+
+type Flags uint
+
+const (
+	FlagUp           Flags = 1 << iota // interface is administratively up
+	FlagBroadcast                      // interface supports broadcast access capability
+	FlagLoopback                       // interface is a loopback interface
+	FlagPointToPoint                   // interface belongs to a point-to-point link
+	FlagMulticast                      // interface supports multicast access capability
+	FlagRunning                        // interface is in running state
+)
+
+var flagNames = []string{
+	"up",
+	"broadcast",
+	"loopback",
+	"pointtopoint",
+	"multicast",
+	"running",
+}
+
+func (f Flags) String() string {
+	s := ""
+	for i, name := range flagNames {
+		if f&(1<<uint(i)) != 0 {
+			if s != "" {
+				s += "|"
+			}
+			s += name
+		}
+	}
+	if s == "" {
+		s = "0"
+	}
+	return s
+}
+
+// Interfaces returns a list of the system's network interfaces.
+func Interfaces() ([]Interface, error) {
+	return nil, errors.New("Interfaces not implemented")
+}
+
+// InterfaceByIndex returns the interface specified by index.
+//
+// On Solaris, it returns one of the logical network interfaces
+// sharing the logical data link; for more precision use
+// InterfaceByName.
+func InterfaceByIndex(index int) (*Interface, error) {
+	return nil, errors.New("InterfaceByIndex not implemented")
+}