Pull sync generated syscalls

This moves all the current users of
$GOROOT/src/syscall/mksyscall_windows.go to instead use
golang.org/x/sys/windows/mkwinsyscall, as directed by the version of the
former in Go 1.15.

It also syncs the local forks of mksyscall_windows.go with the latest
version of golang.org/x/sys/windows/mkwinsyscall/mkwinsyscall.go, so
that the local patches can be easily seen in a side-by-side comparison.
Significant changes compared to the in-tree forked versions:
* *bool parameters are read back through a temp-var, not directly like
  other pointer parameters.
* ?-suffixed function names support testing for function presence before
  calling. This replaces a local implementation of this in
  pkg/security, which was not actually used anyway. The upstream version
  correctly supports functions that don't already have an error return.
* `errnoErr(0)` is now useful, so each call of `errnoErr` doesn't need
  to be protected with a check for 0 first.
* The generated functions are now sorted. This of course produced a
  *lot* of churn in the generated files.

vhd\vhd.go was changed to generate syscalls into zvhd_windows.go, since
regeneration removes the build tag added by hand in
9d8277341f.

After all that, I also ran
```
go generate . .\pkg\etw\ .\pkg\process\ .\pkg\security\ .\vhd\
```
to update all the existing generated code.

Signed-off-by: Paul "TBBle" Hampson <Paul.Hampson@Pobox.com>

vhd/zvhd_windows.go

@@ -0,0 +1,106 @@
+// Code generated by 'go generate'; DO NOT EDIT.
+
+package vhd
+
+import (
+	"syscall"
+	"unsafe"
+
+	"golang.org/x/sys/windows"
+)
+
+var _ unsafe.Pointer
+
+// Do the interface allocations only once for common
+// Errno values.
+const (
+	errnoERROR_IO_PENDING = 997
+)
+
+var (
+	errERROR_IO_PENDING error = syscall.Errno(errnoERROR_IO_PENDING)
+	errERROR_EINVAL     error = syscall.EINVAL
+)
+
+// errnoErr returns common boxed Errno values, to prevent
+// allocations at runtime.
+func errnoErr(e syscall.Errno) error {
+	switch e {
+	case 0:
+		return errERROR_EINVAL
+	case errnoERROR_IO_PENDING:
+		return errERROR_IO_PENDING
+	}
+	// TODO: add more here, after collecting data on the common
+	// error values see on Windows. (perhaps when running
+	// all.bat?)
+	return e
+}
+
+var (
+	modvirtdisk = windows.NewLazySystemDLL("virtdisk.dll")
+
+	procAttachVirtualDisk          = modvirtdisk.NewProc("AttachVirtualDisk")
+	procCreateVirtualDisk          = modvirtdisk.NewProc("CreateVirtualDisk")
+	procDetachVirtualDisk          = modvirtdisk.NewProc("DetachVirtualDisk")
+	procGetVirtualDiskPhysicalPath = modvirtdisk.NewProc("GetVirtualDiskPhysicalPath")
+	procOpenVirtualDisk            = modvirtdisk.NewProc("OpenVirtualDisk")
+)
+
+func attachVirtualDisk(handle syscall.Handle, securityDescriptor *uintptr, attachVirtualDiskFlag uint32, providerSpecificFlags uint32, parameters *AttachVirtualDiskParameters, overlapped *syscall.Overlapped) (err error) {
+	r1, _, e1 := syscall.Syscall6(procAttachVirtualDisk.Addr(), 6, uintptr(handle), uintptr(unsafe.Pointer(securityDescriptor)), uintptr(attachVirtualDiskFlag), uintptr(providerSpecificFlags), uintptr(unsafe.Pointer(parameters)), uintptr(unsafe.Pointer(overlapped)))
+	if r1 != 0 {
+		err = errnoErr(e1)
+	}
+	return
+}
+
+func createVirtualDisk(virtualStorageType *VirtualStorageType, path string, virtualDiskAccessMask uint32, securityDescriptor *uintptr, createVirtualDiskFlags uint32, providerSpecificFlags uint32, parameters *CreateVirtualDiskParameters, overlapped *syscall.Overlapped, handle *syscall.Handle) (err error) {
+	var _p0 *uint16
+	_p0, err = syscall.UTF16PtrFromString(path)
+	if err != nil {
+		return
+	}
+	return _createVirtualDisk(virtualStorageType, _p0, virtualDiskAccessMask, securityDescriptor, createVirtualDiskFlags, providerSpecificFlags, parameters, overlapped, handle)
+}
+
+func _createVirtualDisk(virtualStorageType *VirtualStorageType, path *uint16, virtualDiskAccessMask uint32, securityDescriptor *uintptr, createVirtualDiskFlags uint32, providerSpecificFlags uint32, parameters *CreateVirtualDiskParameters, overlapped *syscall.Overlapped, handle *syscall.Handle) (err error) {
+	r1, _, e1 := syscall.Syscall9(procCreateVirtualDisk.Addr(), 9, uintptr(unsafe.Pointer(virtualStorageType)), uintptr(unsafe.Pointer(path)), uintptr(virtualDiskAccessMask), uintptr(unsafe.Pointer(securityDescriptor)), uintptr(createVirtualDiskFlags), uintptr(providerSpecificFlags), uintptr(unsafe.Pointer(parameters)), uintptr(unsafe.Pointer(overlapped)), uintptr(unsafe.Pointer(handle)))
+	if r1 != 0 {
+		err = errnoErr(e1)
+	}
+	return
+}
+
+func detachVirtualDisk(handle syscall.Handle, detachVirtualDiskFlags uint32, providerSpecificFlags uint32) (err error) {
+	r1, _, e1 := syscall.Syscall(procDetachVirtualDisk.Addr(), 3, uintptr(handle), uintptr(detachVirtualDiskFlags), uintptr(providerSpecificFlags))
+	if r1 != 0 {
+		err = errnoErr(e1)
+	}
+	return
+}
+
+func getVirtualDiskPhysicalPath(handle syscall.Handle, diskPathSizeInBytes *uint32, buffer *uint16) (err error) {
+	r1, _, e1 := syscall.Syscall(procGetVirtualDiskPhysicalPath.Addr(), 3, uintptr(handle), uintptr(unsafe.Pointer(diskPathSizeInBytes)), uintptr(unsafe.Pointer(buffer)))
+	if r1 != 0 {
+		err = errnoErr(e1)
+	}
+	return
+}
+
+func openVirtualDisk(virtualStorageType *VirtualStorageType, path string, virtualDiskAccessMask uint32, openVirtualDiskFlags uint32, parameters *OpenVirtualDiskParameters, handle *syscall.Handle) (err error) {
+	var _p0 *uint16
+	_p0, err = syscall.UTF16PtrFromString(path)
+	if err != nil {
+		return
+	}
+	return _openVirtualDisk(virtualStorageType, _p0, virtualDiskAccessMask, openVirtualDiskFlags, parameters, handle)
+}
+
+func _openVirtualDisk(virtualStorageType *VirtualStorageType, path *uint16, virtualDiskAccessMask uint32, openVirtualDiskFlags uint32, parameters *OpenVirtualDiskParameters, handle *syscall.Handle) (err error) {
+	r1, _, e1 := syscall.Syscall6(procOpenVirtualDisk.Addr(), 6, uintptr(unsafe.Pointer(virtualStorageType)), uintptr(unsafe.Pointer(path)), uintptr(virtualDiskAccessMask), uintptr(openVirtualDiskFlags), uintptr(unsafe.Pointer(parameters)), uintptr(unsafe.Pointer(handle)))
+	if r1 != 0 {
+		err = errnoErr(e1)
+	}
+	return
+}