// Minimum alignment for a struct is 1 byte.
	align = 1

	var buf strings.Builder
	buf.WriteString("struct {")
	fld := make([]*ast.Field, 0, 2*len(dt.Field)+1) // enough for padding around every field
	sizes := make([]int64, 0, 2*len(dt.Field)+1)
	off := int64(0)

	// Rename struct fields that happen to be named Go keywords into
	// _{keyword}.  Create a map from C ident -> Go ident. The Go ident will