* windows-nat.c (windows_make_so): Use gdb_bfd_open.

	* windows-nat.c (windows_make_so): Use gdb_bfd_open.
	* symfile.c (bfd_open_maybe_remote): Use gdb_bfd_open.
	(symfile_bfd_open): Likewise.
	(generic_load): Likewise.
	* solib.c (solib_bfd_fopen): Use gdb_bfd_open.
	* solib-pa64.c (pa64_solib_create_inferior_hook): Use
	gdb_bfd_open.
	* solib-darwin.c (darwin_solib_get_all_image_info_addr_at_init):
	Use gdb_bfd_open.
	* rs6000-nat.c (add_vmap): Use gdb_bfd_open.
	* remote-mips.c (mips_load_srec): Use gdb_bfd_open.
	(pmon_load_fast): Likewise.
	* remote-m32r-sdi.c (m32r_load): Use gdb_bfd_open.
	* procfs.c (insert_dbx_link_bpt_in_file): Use gdb_bfd_open.
	* machoread.c (macho_symfile_read_all_oso): Use gdb_bfd_open.
	(macho_check_dsym): Likewise.
	* m32r-rom.c (m32r_load): Use gdb_bfd_open.
	(m32r_upload_command): Likewise.
	* gdb_bfd.h (gdb_bfd_cache): Declare.
	* gdb_bfd.c (struct gdb_bfd_data): New.
	(gdb_bfd_cache): New global.
	(struct gdb_bfd_cache_search): New.
	(hash_bfd): New function.
	(eq_bfd): Likewise.
	(gdb_bfd_open): Likewise.
	(gdb_bfd_ref): Allocate a gdb_bfd_data and attach to the BFD.
	(gdb_bfd_unref): Remove closed BFD from cache.  Update for
	gdb_bfd_data.
	* exec.c (exec_file_attach): Use gdb_bfd_open.
	* dsrec.c (load_srec): Use gdb_bfd_open.