Redesign GCC_FUNC_PRINTF_PTR so that it doesn't define HOST_PTR_PRINTF
directly.  Instead, autoconf will only determine whether "%p" works and
its up to machmode.h to base its definition of HOST_PTR_PRINTF on that.
This ensures that machmode.h is always included to get the definition of
HOST_PTR_PRINTF for lossy hosts or cross compiles where "%p" is not
found.
        * aclocal.m4 (GCC_FUNC_PRINTF_PTR): Don't define HOST_PTR_PRINTF.
        Instead, define a new macro HAVE_PRINTF_PTR which only signifies
        whether we have the %p format specifier or not.
        * acconfig.h: Delete stub for HOST_PTR_PRINTF, add HAVE_PRINTF_PTR.
        * machmode.h (HOST_PTR_PRINTF): When determining the definition,
        check HAVE_PRINTF_PTR to see whether "%p" is okay.
        * mips-tfile.c: Include machmode.h to get HOST_PTR_PRINTF.
        * Makefile.in (mips-tfile.o): Depend on machmode.h.

From-SVN: r20953