backtrace.h (backtrace_syminfo_callback): Add symsize argument.

	* backtrace.h (backtrace_syminfo_callback): Add symsize argument.
	* elf.c (elf_syminfo): Pass 0 or sym->size to the callback as
	last argument.
	* btest.c (struct symdata): Add size field.
	(callback_three): Add symsize argument.  Copy it to the data->size
	field.
	(f23): Set symdata.size to 0.
	(test5): Likewise.  If sizeof (int) > 1, lookup address of
	((uintptr_t) &global) + 1.  Verify symdata.val and symdata.size
	values.

From-SVN: r205028