[patch] Fix internal error on library without dirname

[Tom Tromey]

>>>>> "Jan" == Jan Kratochvil <jan.kratochvil@redhat.com> writes:

Jan> Starting program: [...]
Jan> ../../gdb/symfile.c:1326: internal-error: find_separate_debug_file_by_debuglink: Assertion `i >= 0 && IS_DIR_SEPARATOR (dir[i])' failed.
Jan> A problem internal to GDB has been detected,

Thanks.

Jan> I believe it could go for 7.2.

I agree.

Jan> 	* symfile.c (find_separate_debug_file_by_debuglink): Remove
Jan> 	a gdb_assert call, new comment.

There is a comment just before the loop above the assert that is now
invalid:

  /* Strip off the final filename part, leaving the directory name,
     followed by a slash.  Objfile names should always be absolute and
     tilde-expanded, so there should always be a slash in there
     somewhere.  */

This patch is ok with some suitable change to this comment.

Tom