Hi,

Patch improves performance of the separate debug info files verification as it
does not need to read and checksum the whole .debug file, it only reads its id.

This part may be questionable:
-  debugfile = find_separate_debug_file (objfile); 
+  /* If the file has its own symbol tables it has no separate debug info.  */
+  if (objfile->psymtabs == NULL)
+    debugfile = find_separate_debug_file (objfile);

So far .gnu_debuglink existed only in the main file (not the .debug file) and
it existed only if the debug info was stripped to a separate file from it.
debug-id exists always and even both in the main file and the .debug file,
therefore the former code above would deadlock in a loop.  Not sure if
`PSYMTABS == NULL' is the right condition.  According to my experiments on
GNU/Linux it should be correct.

--- background:

There is now a new build-id feature since binutils-2.17.50.0.18 with section
`.note.gnu.build-id' used for finding the matching binaries for a core file.
	http://fedoraproject.org/wiki/RolandMcGrath/BuildID

Patch uses the recently approved BFD `.note.gnu.build-id' parsing:
	http://sourceware.org/ml/binutils/2007-08/msg00296.html


Regards,
Jan