JBD: Increase name buffer to 32K

Increase the size of the JDB kernel object names buffer. The original size was
too small for some Genode scenarios and caused missing thread names in the
kernel debugger thread list.

Was: 'jdb_kobject_names.patch'

kernel/fiasco/src/jdb/jdb_kobject_names.cpp

@@ -43,7 +43,7 @@ IMPLEMENTATION:
 
 enum
 {
-  Name_buffer_size = 8192,
+  Name_buffer_size = 4*8192,
   Name_entries = Name_buffer_size / sizeof(Jdb_kobject_name),
 };