darwin.h (LINK_COMMAND_SPEC): Don't do dwarf stuff on pre-darwin9 system, unless the user asks for it directly.

	* config/darwin.h (LINK_COMMAND_SPEC): Don't do dwarf stuff on
	pre-darwin9 system, unless the user asks for it directly.
	(PREFERRED_DEBUGGING_TYPE): Likewise.
	* config/i386/darwin.h (PREFERRED_DEBUGGING_TYPE): Likewise.
	* config.gcc: Add suppport for darwin9.h.
	* config/darwin9.h: Add.
	* doc/install.texi (Specific): Clarify darwin documentation.

From-SVN: r118917