delete mode 100644 std/os/freebsd.zig
 create mode 100644 std/os/freebsd/errno.zig
 create mode 100644 std/os/freebsd/index.zig
 create mode 100644 std/os/freebsd/x86_64.zig
 delete mode 100644 std/os/freebsd_errno.zig
 delete mode 100644 std/os/freebsd_i386.zig
 delete mode 100644 std/os/freebsd_x86_64.zig