* c-common.c (c_common_init): Set options->unsigned_wchar.
	* cppinit.c (cpp_create_reader): Default unsigned_wchar,
	group target dependencies.
	(init_builtins, cpp_handle_option): Update.
	* cpplex.c (cpp_interpret_charconst): Update.
	* cpplib.h (struct cpp_options): Add unsigned_wchar, rename
	signed_char to unsigned_char, group target dependencies.
	* defaults.h (WCHAR_UNSIGNED): Remove.
	* system.h (WCHAR_UNSIGNED, MAX_CHAR_TYPE_SIZE): Poison.
config:
	* freebsd.h, interix.h, alpha/freebsd.h, arm/freebsd.h,
	i386/386bsd.h, i386/beos-elf.h, i386/bsd386.h, i386/cygwin.h,
	i386/djgpp.h, i386/freebsd-aout.h, i386/i386-interix.h,
	i386/win32.h, ia64/freebsd.h, mips/netbsd.h, rs6000/freebsd.h,
	sh/elf.h, sh/sh.h, sparc/freebsd.h: Remove WCHAR_UNSIGNED.
doc:
	* tm.texi: Remove MAX_CHAR_TYPE_SIZE.

From-SVN: r53271