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.