[Bug middle-end/56524] [4.8 Regression] Compiler ICE when compiling with -mips16

["aldyh at gcc dot gnu.org" <gcc-bugzilla at gcc dot gnu dot org>]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=56524

--- Comment #3 from Aldy Hernandez <aldyh at gcc dot gnu.org> 2013-03-06 17:54:41 UTC ---
This is ICEing here:

  /* ?? If this fails, we should temporarily restore the default
     target first (set_cfun (NULL) ??), do the rest of this function,
     and then restore it.  */
  gcc_assert (this_target_optabs == &default_target_optabs);

In this case, this_target_optabs is being set in:

  mips_set_mips16_mode() ->
    save_target_globals_default_opts() ->
      save_target_globals() ->
        restore_target_globals() 
             ...
             this_target_optabs = g->optabs;

We can't do exactly as the comment above the ICE says, since cfun isn't even
set at this point (we are being called from the parser).