windows: use //go:uintptrescapes comment

CL 24551 introduced //go:uintptrescapes comment to make
syscall.Proc.Call and syscall.LazyProc.Call parameters escape.
Use new comment in this package too.

Updates golang/go#16035.

Change-Id: I57ec3b4778195ca4a1ce9a8eec331f0f69285926
Reviewed-on: https://go-review.googlesource.com/24870
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>

windows/dll_windows.go

@@ -114,6 +114,8 @@ func (p *Proc) Addr() uintptr {
 	return p.addr
 }
 
+//go:uintptrescapes
+
 // Call executes procedure p with arguments a. It will panic, if more then 15 arguments
 // are supplied.
 //
@@ -293,6 +295,8 @@ func (p *LazyProc) Addr() uintptr {
 	return p.proc.Addr()
 }
 
+//go:uintptrescapes
+
 // Call executes procedure p with arguments a. It will panic, if more then 15 arguments
 // are supplied.
 //