// VM/Y rejects X index register.
	VPGATHERQQ Y2, (BP)(X7*2), Y1   // ERROR "invalid instruction"
	VPGATHERDD Y5, -8(X14*8), Y6    // ERROR "invalid instruction"
	// No VSIB for legacy instructions.
	MOVL (AX)(X0*1), AX             // ERROR "invalid instruction"
	MOVL (AX)(Y0*1), AX             // ERROR "invalid instruction"
	// VSIB/VM is invalid without vector index.

func (tw *Writer) WriteHeader(hdr *Header) error {
	if err := tw.Flush(); err != nil {
		return err
	}
	tw.hdr = *hdr // Shallow copy of Header

	// Avoid usage of the legacy TypeRegA flag, and automatically promote
	// it to use TypeReg or TypeDir.
	if tw.hdr.Typeflag == TypeRegA {
		if strings.HasSuffix(tw.hdr.Name, "/") {
			tw.hdr.Typeflag = TypeDir
		} else {
			tw.hdr.Typeflag = TypeReg

	//
	// When reading, an extended timestamp is preferred over the legacy MS-DOS
	// date field, and the offset between the times is used as the timezone.
	// If only the MS-DOS date is present, the timezone is assumed to be UTC.
	//
	// When writing, an extended timestamp (which is timezone-agnostic) is
	// always emitted. The legacy MS-DOS date field is encoded according to the
	// location of the Modified time.

		}
	}

	msdosModified := msDosTimeToTime(f.ModifiedDate, f.ModifiedTime)
	f.Modified = msdosModified
	if !modified.IsZero() {
		f.Modified = modified.UTC()

		// If legacy MS-DOS timestamps are set, we can use the delta between
		// the legacy and extended versions to estimate timezone offset.
		//
		// A non-UTC timezone is always used (even if offset is zero).
		// Thus, FileHeader.Modified.Location() == time.UTC is useful for

	f.Close()
	if err != nil {
		log.Fatal(err)
	}

	// <= go 1.7 doesn't embed the contentID or actionID, so no slash is present
	if !strings.Contains(id, "/") {
		log.Fatalf("%s: build ID is a legacy format...binary too old for this tool", file)
	}

	newID := id[:strings.LastIndex(id, "/")] + "/" + buildid.HashToString(hash)
	if len(newID) != len(id) {
		log.Fatalf("%s: build ID length mismatch %q vs %q", file, id, newID)

		// Contrary to the FileHeader.SetModTime method, we intentionally
		// do not convert to UTC, because we assume the user intends to encode
		// the date using the specified timezone. A user may want this control
		// because many legacy ZIP readers interpret the timestamp according
		// to the local timezone.
		//
		// The timezone is only non-UTC if a user directly sets the Modified
		// field directly themselves. All other approaches sets UTC.

				hdr.Name = gnuLongName
			}
			if gnuLongLink != "" {
				hdr.Linkname = gnuLongLink
			}
			if hdr.Typeflag == TypeRegA {
				if strings.HasSuffix(hdr.Name, "/") {
					hdr.Typeflag = TypeDir // Legacy archives use trailing slash for directories
				} else {
					hdr.Typeflag = TypeReg
				}
			}

			// The extended headers may have updated the size.

<p>
  <code>go</code> <code>get</code> is no longer supported outside of a module in the
  legacy <code>GOPATH</code> mode (that is, with <code>GO111MODULE=off</code>).
  Other build commands, such as <code>go</code> <code>build</code> and
  <code>go</code> <code>test</code>, will continue to work indefinitely
  for legacy <code>GOPATH</code> programs.
</p>

<!-- CL 518776 -->
<p>

			// Special 3-operand jumps.
			// a[1] is a register number expressed as a constant or register value
			target = &a[2]
			prog.From = a[0]
			if a[0].Type != obj.TYPE_CONST {
				// Legacy code may use a plain constant, accept it, and coerce
				// into a constant. E.g:
				//   BC 4,...
				// into
				//   BC $4,...
				prog.From = obj.Addr{
					Type:   obj.TYPE_CONST,