gdb/

gdb/
	* symfile.c (addr_section_name): New function.
	(addrs_section_compar): Use it.
	(addr_info_make_relative): Use it.  Move variable sect_name into a more
	inner block.  Make ".dynbss" and ".sdynbss" checks more strict.

gdb/testsuite/
	* gdb.base/prelink-lib.c (copyreloc): New initialized variable.
	* gdb.base/prelink.c (copyreloc, bssvar, bssvarp): New variables.
	(main): Use copyreloc.
	* gdb.base/prelink.exp (split debug of executable)
	(.dynbss vs. .bss address shift): New tests.