Pull in a fix (still under GPLv2) for a double free in gdb, leading to

an assert, which can occur if you repeatedly dlopen() and dlclose() a
.so file in a tight loop.  This was reported on freebsd-current@ by
Alexandre Martins, with a sample to reproduce the behaviour.

Obtained from:	http://sourceware.org/git/?p=gdb.git;a=commit;h=a6f2cbb341520f8e100f4b8305979dd6207a79e8

contrib/gdb/gdb/target.c

@@ -1425,6 +1425,13 @@ target_resize_to_sections (struct target_ops *target, int num_added)
 	      (*t)->to_sections_end = target->to_sections_end;
 	    }
 	}
+      /* There is a flattened view of the target stack in current_target,
+	 so its to_sections pointer might also need updating. */
+      if (current_target.to_sections == old_value)
+	{
+	  current_target.to_sections = target->to_sections;
+	  current_target.to_sections_end = target->to_sections_end;
+	}
     }
 
   return old_count;