* newlib.hin: (_WANT_IO_POS_ARGS): New define.
(_WANT_IO_LONG_LONG): Ditto.
(_WANT_IO_LONG_DOUBLE): Ditto.
* configure.in: Add new configuration options
--enable-newlib-io-long-long and --enable-newlib-io-long-double
which tie to new defines in newlib.hin.
* configure: Regenerated.
* configure.host: Add checks for new configuration options. Also
fix up check for --enable-newlib-io-pos-args so configuration
option will override any default for a given platform.
Remove defining compiler flags for the _WANT_IO* options.
* libc/stdio/vfprintf.c: Change to use new newlib.hin defines
instead of looking for old compiler flags.
* libc/stdio/vfscanf.c: Ditto.
* libc/stdio/vfieeefp.h: Ditto.
* libc/machine/powerpc/vfprintf.c: Ditto.
* libc/machine/powerpc/vfscanf.c: Ditto.