Handle missing vfprintf() & _doprnt() functions with linked in modules,

Handle missing vfprintf() & _doprnt() functions with linked in modules,

plus do some general cleanup of variable argument handling.
        * aclocal.m4 (GCC_FUNC_VFPRINTF_DOPRNT): New macro.
        * configure.in: Add a call to GCC_FUNC_VFPRINTF_DOPRNT.
        (AC_CHECK_HEADERS): Remove unused check for varargs.h,sys/varargs.h.
        (AC_CHECK_FUNCS): Remove unused check for vprintf.
        * Makefile.in: Add support for linking in vfprintf.c and doprint.c.
        (cccp.o): Depend on gansidecl.h.
        (cexp.o): Likewise.
        * cccp.c: Convert from using PRINTF_ALIST/PRINTF_DCL to VPROTO as
        per the rest of gcc source.
        * cexp.y: Likewise.  Include gansidecl.h and remove all code made
        redundant.
        * cccp.c: Remove checks for HAVE_VPRINTF and the associated code
        used when vfprintf is missing.
        * cexp.y: Likewise.
        * gcc.c: Likewise.
        * genattrtab.c: Likewise.
        * mips-tfile.c: Likewise.
        * toplev.c: Likewise.
        * vfprintf.c: New file.
        * doprint.c: Likewise.

From-SVN: r19610