Adapt the MS-DOS build to the latest changes.

Adapt the MS-DOS build to the latest changes.

  msdos/mainmake.v2 (bootstrap-clean): Do a maintainer-clean in lib, not
  bootstrap-clean (which doesn't exist).
  msdos/inttypes.h (PRIuMAX) [__DJGPP__ < 2.04]: Define to "llu".
  msdos/sedleim.inp (MKDIR_P): Edit to DOS "md" command.
  msdos/sed1v2.inp: (LIB_CLOCK_GETTIME): Edit to empty.
  Remove lines that invoke PAXCTL.
  (clean): Fix recipe not to run Unixy shell commands.
  msdos/sed2v2.inp (GETTIMEOFDAY_TIMEZONE): Edit to 'struct timezone'.
  (HAVE_STRNCASECMP): Edit to 1.
  msdos/sed3v2.inp (LIB_CLOCK_GETTIME): Edit to empty.
  (C_SWITCH_SYSTEM): Add "-I../msdos".
  msdos/sedlibmk.inp (GNULIB_GETTIMEOFDAY, GNULIB_PSELECT)
  (GNULIB_SELECT, HAVE_STRUCT_TIMEVAL, HAVE_SYS_SELECT_H)
  (HAVE_SYS_TIME_H, NEXT_AS_FIRST_DIRECTIVE_SYS_SELECT_H)
  (NEXT_AS_FIRST_DIRECTIVE_SYS_TIME_H, NEXT_SYS_SELECT_H)
  (NEXT_SYS_TIME_H, REPLACE_GETTIMEOFDAY, REPLACE_PSELECT)
  (REPLACE_STRUCT_TIMEVAL): Edit to appropriate values.
  (BUILT_SOURCES): Edit out sys/select.h and sys/time.h.
  (mostlyclean-local, distclean-generic): Fix recipe not to run
  Unixy shell commands.

  src/sysselect.h [DOS_NT]: Don't include sys/select.h.
  src/sysselect.h (pselect) [!HAVE_PSELECT]: Redirect to sys_select.
  src/sysdep.c: Don't include dos.h and dosfns.h.
  src/process.c (sys_select):
  src/msdos.c (sys_select): Accept one more argument and ignore it.
  src/msdos.c (event_timestamp, sys_select): Use gnulib's gettime;
  adapt data types and code to that.
  src/dosfns.c:
  src/msdos.c (gettime, settime): Define away the prototypes in dos.h,
  which clashes with the gnulib function of the same name.
  src/ w32proc.c (sys_select): Accept and ignore one more argument.
  src/w32.c (emacs_gnutls_pull): Call select with one more argument.

  lisp/emacs-lisp/timer.el (timer-until): Subtract results of
  float-time, instead of taking float-time of the result of
  time-subtract, since float-time signals an error for negative time
  arguments.