Add a new function to the BFD library to allow users access to the COFF...

Add a new function to the BFD library to allow users access to the COFF internal_extra_pe_outhdr structure.

	* cofflink.c (bfd_coff_get_internal_extra_pe_aouthdr): New
	function.
	* libbfd-in.h (bfd_coff_get_internal_extra_pe_aouthdr): Prototype.
	* libbfd.h: Regenerate.