Fix gas/gcc unwind/EH discrepancies. And a shared library build problem.

Fix gas/gcc unwind/EH discrepancies.  And a shared library build problem.

	* frame.h (struct unwind_info_ptr): Collapse version, flags, and length
	fields into header field.
	(IA64_UNW_HDR_LENGTH, IA64_UNW_HDR_FLAGS, IA64_UNW_HDR_VERSION): New
	macros to access length, flags, and version info from header field.
	* config/ia64/crtbegin.asm (__do_frame_setup_aux): Delete here.
	...

From-SVN: r34441