Windows: work around Go 1.6.2/Nano Server TP5 issue

This works around golang/go#15286 by explicitly loading shell32.dll at
load time, ensuring that syscall can load it dynamically during process
startup.

Signed-off-by: John Starks <jostarks@microsoft.com>
Signed-off-by: Antonio Murdaca <runcom@redhat.com>
Upstream-commit: 9b1a322d9e
Component: cli

components/cli/docker_windows.go

@@ -1,5 +1,18 @@
 package main
 
 import (
+	"sync/atomic"
+
 	_ "github.com/docker/docker/autogen/winresources/docker"
 )
+
+//go:cgo_import_dynamic main.dummy CommandLineToArgvW%2 "shell32.dll"
+
+var dummy uintptr
+
+func init() {
+	// Ensure that this import is not removed by the linker. This is used to
+	// ensure that shell32.dll is loaded by the system loader, preventing
+	// go#15286 from triggering on Nano Server TP5.
+	atomic.LoadUintptr(&dummy)
+}