remove 1.6 support for channelz (#2242)

ChannelZ is a debugging feature in grpc. It has not had appengine support; this commit
removes its support for 1.6, too. This change is because in a recent sys/unix commit
1.6 support was broken.

.travis.yml

@@ -4,6 +4,7 @@ matrix:
   include:
   - go: 1.10.x
     env: VET=1 RACE=1
+  - go: 1.6.x
   - go: 1.7.x
   - go: 1.8.x
   - go: 1.9.x

channelz/service/func_linux.go

@@ -1,4 +1,4 @@
-// +build !appengine
+// +build !appengine,go1.7
 
 /*
  *

channelz/service/func_nonlinux.go

@@ -1,4 +1,4 @@
-// +build !linux appengine
+// +build !linux appengine !go1.7
 
 /*
  *

channelz/service/service_sktopt_test.go

@@ -1,4 +1,4 @@
-// +build linux,!appengine
+// +build linux,!appengine,go1.7
 // +build 386 amd64
 
 /*

channelz/service/util_sktopt_386_test.go

@@ -1,4 +1,4 @@
-// +build 386,linux,!appengine
+// +build 386,linux,!appengine,go1.7
 
 /*
  *

channelz/service/util_sktopt_amd64_test.go

@@ -1,4 +1,4 @@
-// +build amd64,linux,!appengine
+// +build amd64,linux,!appengine,go1.7
 
 /*
  *

internal/channelz/types_linux.go

@@ -1,4 +1,4 @@
-// +build !appengine
+// +build !appengine,go1.7
 
 /*
  *

internal/channelz/types_nonlinux.go

@@ -1,4 +1,4 @@
-// +build !linux appengine
+// +build !linux appengine !go1.7
 
 /*
  *

internal/syscall/syscall_linux.go

@@ -1,4 +1,4 @@
-// +build !appengine
+// +build !appengine,go1.7
 
 /*
  *

internal/syscall/syscall_nonlinux.go

@@ -1,4 +1,4 @@
-// +build !linux appengine
+// +build !linux appengine !go1.7
 
 /*
  *