shift flag_next/gnu_runtime to modern opts system.

shift flag_next/gnu_runtime to modern opts system.

gcc:

	* doc/tm.texi.in (NEXT_OBJC_RUNTIME): Update macro description.
	* doc/tm.texi: Regenerate.
	* flags.h (flag_next_runtime): Remove references.
	* toplev.c: Likewise.
	* defaults.h (NEXT_OBJC_RUNTIME): Provide default.
	* gccspec.c (lang_specific_driver): Adjust use of NEXT_OBJC_RUNTIME.
	* config/darwin.c (darwin_override_options): Provide default
	Objective-C abi settings and target conflict checks.
	* config/darwin.h (SUBTARGET_C_COMMON_OVERRIDE_OPTIONS): Remove unused
	code. Adjust indenting.

gcc/c-family:

	* c.opt (fgnu-runtime): Provide full description.
	(fnext-runtime): Likewise.
	* c-opts.c (OPT_fgnu_runtime, OPT_fnext_runtime) Remove.

From-SVN: r181837