tailcfg: add Hostinfo.WireIngress bool

Yet unused. Future optimization for control.

Updates tailscale/corp#7515

Change-Id: Icd755aa8b1d6ca61d16dfc124c28c9c56ebdfee5
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>

tailcfg/tailcfg.go

@@ -515,6 +515,7 @@ type Hostinfo struct {
 	ShieldsUp       bool           `json:",omitempty"` // indicates whether the host is blocking incoming connections
 	ShareeNode      bool           `json:",omitempty"` // indicates this node exists in netmap because it's owned by a shared-to user
 	NoLogsNoSupport bool           `json:",omitempty"` // indicates that the user has opted out of sending logs and support
+	WireIngress     bool           `json:",omitempty"` // indicates that the node wants the option to receive ingress connections
 	GoArch          string         `json:",omitempty"` // the host's GOARCH value (of the running binary)
 	GoVersion       string         `json:",omitempty"` // Go version binary was built with
 	RoutableIPs     []netip.Prefix `json:",omitempty"` // set of IP ranges this client can route

tailcfg/tailcfg_clone.go

@@ -134,6 +134,7 @@ var _HostinfoCloneNeedsRegeneration = Hostinfo(struct {
 	ShieldsUp       bool
 	ShareeNode      bool
 	NoLogsNoSupport bool
+	WireIngress     bool
 	GoArch          string
 	GoVersion       string
 	RoutableIPs     []netip.Prefix

tailcfg/tailcfg_test.go

@@ -48,6 +48,7 @@ func TestHostinfoEqual(t *testing.T) {
 		"ShieldsUp",
 		"ShareeNode",
 		"NoLogsNoSupport",
+		"WireIngress",
 		"GoArch",
 		"GoVersion",
 		"RoutableIPs",

tailcfg/tailcfg_view.go

@@ -271,6 +271,7 @@ func (v HostinfoView) Hostname() string       { return v.ж.Hostname }
 func (v HostinfoView) ShieldsUp() bool        { return v.ж.ShieldsUp }
 func (v HostinfoView) ShareeNode() bool       { return v.ж.ShareeNode }
 func (v HostinfoView) NoLogsNoSupport() bool  { return v.ж.NoLogsNoSupport }
+func (v HostinfoView) WireIngress() bool      { return v.ж.WireIngress }
 func (v HostinfoView) GoArch() string         { return v.ж.GoArch }
 func (v HostinfoView) GoVersion() string      { return v.ж.GoVersion }
 func (v HostinfoView) RoutableIPs() views.IPPrefixSlice {
@@ -304,6 +305,7 @@ var _HostinfoViewNeedsRegeneration = Hostinfo(struct {
 	ShieldsUp       bool
 	ShareeNode      bool
 	NoLogsNoSupport bool
+	WireIngress     bool
 	GoArch          string
 	GoVersion       string
 	RoutableIPs     []netip.Prefix