Change signature of bfd crc functions

The crc calculated is 32 bits.  Replace uses of unsigned long with
uint32_t.  Also use bfd_byte* for buffers.

bfd/
	* opncls.c (bfd_calc_gnu_debuglink_crc32): Use stdint types.
	(bfd_get_debug_link_info_1, bfd_get_debug_link_info): Likewise.
	(separate_debug_file_exists, bfd_follow_gnu_debuglink): Likewise.
	(bfd_fill_in_gnu_debuglink_section): Likewise.
	* bfd-in2.h: Regenerate.
gdb/
	* auto-load.c (auto_load_objfile_script): Update type of
	bfd_get_debug_link_info argument.
	* symfile.c (find_separate_debug_file_by_debuglink): Likewise.
	* gdb_bfd.c (get_file_crc): Update type of
	bfd_calc_gnu_debuglink_crc32 argument.