* i386/go32-rtems.h, i386/rtems.h, i960/rtems.h,
        m68k/rtems.h, mips/rtems64.h, pa/rtems.h, rs6000/rtems.h,
        sparc/rtems.h (subtarget_switches): Added -mrtems as a switch.
        * i960/i960.h: Added SUBTARGET_SWITCHES macro.
        * rs6000/sysv4.h (extra_subtarget_switches): Added new
        macro EXTRA_SUBTARGET_SWITCHES.
        * configure.in (sh*-*-rtems*): New target.
        * sh/rtems.h: New file.
        * sh/sh.h: Added SUBTARGET_SWITCHES macro.
        * configure: Rebuilt.

From-SVN: r15006