Re-implement gdbach_dump() so that it prints out the macro values.

Add ``maint print arch'' command.
Add ``gdbarch_register()'' function that also takes gdbarch_dump_tdep().
Use in mips-tdep.c.

gdb/gdbarch.h

@@ -1180,8 +1180,11 @@ extern struct gdbarch_tdep *gdbarch_tdep (struct gdbarch *gdbarch);
    gdbarch'' from the ARCHES list - indicating that the new
    architecture is just a synonym for an earlier architecture (see
    gdbarch_list_lookup_by_info()); a newly created ``struct gdbarch''
-   - that describes the selected architecture (see
-   gdbarch_alloc()). */
+   - that describes the selected architecture (see gdbarch_alloc()).
+
+   The DUMP_TDEP function shall print out all target specific values.
+   Care should be taken to ensure that the function works in both the
+   multi-arch and non- multi-arch cases. */
 
 struct gdbarch_list
 {
@@ -1208,9 +1211,15 @@ struct gdbarch_info
 };
 
 typedef struct gdbarch *(gdbarch_init_ftype) (struct gdbarch_info info, struct gdbarch_list *arches);
+typedef void (gdbarch_dump_tdep_ftype) (struct gdbarch *gdbarch, struct ui_file *file);
 
+/* DEPRECATED - use gdbarch_register() */
 extern void register_gdbarch_init (enum bfd_architecture architecture, gdbarch_init_ftype *);
 
+extern void gdbarch_register (enum bfd_architecture architecture,
+                              gdbarch_init_ftype *,
+                              gdbarch_dump_tdep_ftype *);
+
 
 /* Return a freshly allocated, NULL terminated, array of the valid
    architecture names.  Since architectures are registered during the
@@ -1234,7 +1243,10 @@ extern struct gdbarch_list *gdbarch_list_lookup_by_info (struct gdbarch_list *ar
 extern struct gdbarch *gdbarch_alloc (const struct gdbarch_info *info, struct gdbarch_tdep *tdep);
 
 
-/* Helper function.  Free a partially-constructed ``struct gdbarch''.  */
+/* Helper function.  Free a partially-constructed ``struct gdbarch''.
+   It is assumed that the caller freeds the ``struct
+   gdbarch_tdep''. */
+
 extern void gdbarch_free (struct gdbarch *);
 
 
@@ -1407,6 +1419,6 @@ extern void initialize_current_architecture (void);
 /* gdbarch trace variable */
 extern int gdbarch_debug;
 
-extern void gdbarch_dump (void);
+extern void gdbarch_dump (struct gdbarch *gdbarch, struct ui_file *file);
 
 #endif