cmd/coordinator: update to Go 1.16

Also set the language to 1.16 in the x/build go.mod file.

This is needed to be able to use the //go:embed directive in
coordinator, which will make moving static files much easier.

For golang/go#34744.

Change-Id: I0e627b408fe887ce1d3e0d6b3e032166421a8c41
Reviewed-on: https://go-review.googlesource.com/c/build/+/336390
Trust: Dmitri Shuralyov <dmitshur@golang.org>
Run-TryBot: Dmitri Shuralyov <dmitshur@golang.org>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Carlos Amedee <carlos@golang.org>
diff --git a/cmd/coordinator/Dockerfile b/cmd/coordinator/Dockerfile
index 76dd27c..09e7b15 100644
--- a/cmd/coordinator/Dockerfile
+++ b/cmd/coordinator/Dockerfile
@@ -2,12 +2,9 @@
 # Use of this source code is governed by a BSD-style
 # license that can be found in the LICENSE file.
 
-FROM golang:1.13 AS build
+FROM golang:1.16 AS build
 LABEL maintainer "golang-dev@googlegroups.com"
 
-ENV GO111MODULE=on
-ENV GOPROXY=https://proxy.golang.org
-
 RUN mkdir /gocache
 ENV GOCACHE /gocache
 
diff --git a/cmd/coordinator/builders.go b/cmd/coordinator/builders.go
index 9cf5474..f7e3ea8 100644
--- a/cmd/coordinator/builders.go
+++ b/cmd/coordinator/builders.go
@@ -2,8 +2,8 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-//go:build go1.13 && (linux || darwin)
-// +build go1.13
+//go:build go1.16 && (linux || darwin)
+// +build go1.16
 // +build linux darwin
 
 package main
diff --git a/cmd/coordinator/builders_test.go b/cmd/coordinator/builders_test.go
index d3bee0d..6e51117 100644
--- a/cmd/coordinator/builders_test.go
+++ b/cmd/coordinator/builders_test.go
@@ -2,8 +2,8 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-//go:build go1.13 && (linux || darwin)
-// +build go1.13
+//go:build go1.16 && (linux || darwin)
+// +build go1.16
 // +build linux darwin
 
 package main
diff --git a/cmd/coordinator/coordinator.go b/cmd/coordinator/coordinator.go
index 70d3f94..b60edb4 100644
--- a/cmd/coordinator/coordinator.go
+++ b/cmd/coordinator/coordinator.go
@@ -2,8 +2,8 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-//go:build go1.13 && (linux || darwin)
-// +build go1.13
+//go:build go1.16 && (linux || darwin)
+// +build go1.16
 // +build linux darwin
 
 // The coordinator runs the majority of the Go build system.
diff --git a/cmd/coordinator/coordinator_test.go b/cmd/coordinator/coordinator_test.go
index 609c92f..8addd8b 100644
--- a/cmd/coordinator/coordinator_test.go
+++ b/cmd/coordinator/coordinator_test.go
@@ -2,8 +2,8 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-//go:build go1.13 && (linux || darwin)
-// +build go1.13
+//go:build go1.16 && (linux || darwin)
+// +build go1.16
 // +build linux darwin
 
 package main
diff --git a/cmd/coordinator/dash.go b/cmd/coordinator/dash.go
index d1aa889..e21c9b5 100644
--- a/cmd/coordinator/dash.go
+++ b/cmd/coordinator/dash.go
@@ -2,8 +2,8 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-//go:build go1.13 && (linux || darwin)
-// +build go1.13
+//go:build go1.16 && (linux || darwin)
+// +build go1.16
 // +build linux darwin
 
 // Code interacting with build.golang.org ("the dashboard").
diff --git a/cmd/coordinator/debug.go b/cmd/coordinator/debug.go
index cc67b48..58af015 100644
--- a/cmd/coordinator/debug.go
+++ b/cmd/coordinator/debug.go
@@ -2,8 +2,8 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-//go:build go1.13 && (linux || darwin)
-// +build go1.13
+//go:build go1.16 && (linux || darwin)
+// +build go1.16
 // +build linux darwin
 
 package main
diff --git a/cmd/coordinator/log.go b/cmd/coordinator/log.go
index 929db0f..f17dbc0 100644
--- a/cmd/coordinator/log.go
+++ b/cmd/coordinator/log.go
@@ -2,8 +2,8 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-//go:build go1.13 && (linux || darwin)
-// +build go1.13
+//go:build go1.16 && (linux || darwin)
+// +build go1.16
 // +build linux darwin
 
 package main
diff --git a/cmd/coordinator/metrics.go b/cmd/coordinator/metrics.go
index c9c814e..f6906f4 100644
--- a/cmd/coordinator/metrics.go
+++ b/cmd/coordinator/metrics.go
@@ -2,8 +2,8 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-//go:build go1.13 && (linux || darwin)
-// +build go1.13
+//go:build go1.16 && (linux || darwin)
+// +build go1.16
 // +build linux darwin
 
 package main
diff --git a/cmd/coordinator/modproxy.go b/cmd/coordinator/modproxy.go
index f138eb9..28a8b0b 100644
--- a/cmd/coordinator/modproxy.go
+++ b/cmd/coordinator/modproxy.go
@@ -2,8 +2,8 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-//go:build go1.13 && (linux || darwin)
-// +build go1.13
+//go:build go1.16 && (linux || darwin)
+// +build go1.16
 // +build linux darwin
 
 package main
diff --git a/cmd/coordinator/modproxy_test.go b/cmd/coordinator/modproxy_test.go
index 604243f..6110fd4 100644
--- a/cmd/coordinator/modproxy_test.go
+++ b/cmd/coordinator/modproxy_test.go
@@ -2,8 +2,8 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-//go:build go1.13 && (linux || darwin)
-// +build go1.13
+//go:build go1.16 && (linux || darwin)
+// +build go1.16
 // +build linux darwin
 
 package main
diff --git a/cmd/coordinator/remote.go b/cmd/coordinator/remote.go
index 951790d..861c204 100644
--- a/cmd/coordinator/remote.go
+++ b/cmd/coordinator/remote.go
@@ -2,8 +2,8 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-//go:build go1.13 && (linux || darwin)
-// +build go1.13
+//go:build go1.16 && (linux || darwin)
+// +build go1.16
 // +build linux darwin
 
 // Code related to remote buildlets. See x/build/remote-buildlet.txt
diff --git a/cmd/coordinator/remote_test.go b/cmd/coordinator/remote_test.go
index b615bc9..23e3e42 100644
--- a/cmd/coordinator/remote_test.go
+++ b/cmd/coordinator/remote_test.go
@@ -2,8 +2,8 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-//go:build go1.13 && (linux || darwin)
-// +build go1.13
+//go:build go1.16 && (linux || darwin)
+// +build go1.16
 // +build linux darwin
 
 package main
diff --git a/cmd/coordinator/results.go b/cmd/coordinator/results.go
index ea86d0e..e53e92c 100644
--- a/cmd/coordinator/results.go
+++ b/cmd/coordinator/results.go
@@ -2,8 +2,8 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-//go:build go1.13 && (linux || darwin)
-// +build go1.13
+//go:build go1.16 && (linux || darwin)
+// +build go1.16
 // +build linux darwin
 
 // Code related to the Build Results API.
diff --git a/cmd/coordinator/results_test.go b/cmd/coordinator/results_test.go
index f8d4388..fdde1e1 100644
--- a/cmd/coordinator/results_test.go
+++ b/cmd/coordinator/results_test.go
@@ -2,8 +2,8 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-//go:build go1.13 && (linux || darwin)
-// +build go1.13
+//go:build go1.16 && (linux || darwin)
+// +build go1.16
 // +build linux darwin
 
 package main
diff --git a/cmd/coordinator/sched.go b/cmd/coordinator/sched.go
index 63c706f..99bf403 100644
--- a/cmd/coordinator/sched.go
+++ b/cmd/coordinator/sched.go
@@ -2,8 +2,8 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-//go:build go1.13 && (linux || darwin)
-// +build go1.13
+//go:build go1.16 && (linux || darwin)
+// +build go1.16
 // +build linux darwin
 
 package main
diff --git a/cmd/coordinator/sched_test.go b/cmd/coordinator/sched_test.go
index 6ab2068..a7c57ad 100644
--- a/cmd/coordinator/sched_test.go
+++ b/cmd/coordinator/sched_test.go
@@ -2,8 +2,8 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-//go:build go1.13 && (linux || darwin)
-// +build go1.13
+//go:build go1.16 && (linux || darwin)
+// +build go1.16
 // +build linux darwin
 
 package main
diff --git a/cmd/coordinator/status.go b/cmd/coordinator/status.go
index 6f012f0..be7278c 100644
--- a/cmd/coordinator/status.go
+++ b/cmd/coordinator/status.go
@@ -2,8 +2,8 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-//go:build go1.13 && (linux || darwin)
-// +build go1.13
+//go:build go1.16 && (linux || darwin)
+// +build go1.16
 // +build linux darwin
 
 package main
diff --git a/cmd/coordinator/status_test.go b/cmd/coordinator/status_test.go
index 51da086..83215f6 100644
--- a/cmd/coordinator/status_test.go
+++ b/cmd/coordinator/status_test.go
@@ -2,8 +2,8 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-//go:build go1.13 && (linux || darwin)
-// +build go1.13
+//go:build go1.16 && (linux || darwin)
+// +build go1.16
 // +build linux darwin
 
 package main
diff --git a/go.mod b/go.mod
index 7e5c34c..3d445c9 100644
--- a/go.mod
+++ b/go.mod
@@ -1,6 +1,6 @@
 module golang.org/x/build
 
-go 1.12
+go 1.16
 
 require (
 	cloud.google.com/go v0.54.0