* objc-act.c (objc_build_struct): New function.
        (objc_derived_from_p): Likewise.
        (objc_build_component_ref): Likewise.
        (objc_copy_binfo): Likewise.
        (objc_xref_basetypes): Likewise.
        (objc_lookup_protocol): Likewise.
        (objc_compare_protocols): Likewise.
        (objc_volatilize_decl): Likewise.
        (encode_aggregate_fields): Likewise.
        (volatilized_hash): Likewise.
        (volatilized_eq): Likewise.
        (objc_compare_types): Likewise.
        (objc_type_quals_match): Likewise.
        (DERIVED_FROM_P): New ObjC macro, corresponding to C++ macro
        of same name.
        (get_class_ivars): Add second parameter indicating if entire
        hierarchy is desired.
        (struct volatilized_type): New type.
        (volatilized_htab): New hash table.
        (objc_types_compatible_p, objc_comptypes): Remove functions.
        (synth_module_prologue): Do not initialize 'unused_list'.
        (objc_get_class_reference): Fix ObjC++ impedance mismatches.
        (objc_declare_alias): Implement as a typedef.
        (objc_substitute_decl, objc_gimplify_expr): Reformat.
        (objc_get_class_ivars): Adjust call to get_class_ivars().
        (next_sjlj_build_enter_and_setjmp, synth_forward_declarations,
        build_ivar_reference, get_super_receiver): Call
        objc_build_component_ref() instead of build_component_ref().
        (objc_begin_catch_clause): Use DERIVED_FROM_P() instead of
        objc_comptypes().
        (build_private_template): Call objc_build_struct() instead of
        start_struct() and finish_struct().
        (hash_init): Initialize volatilized_htab.
        (objc_is_public): Adjust calls to objc_get_ivars(); adjust
        ObjC++ impedance mismatches.
        (encode_aggregate_within): Streamline by calling
        encode_aggregate_fields().
        * objc-act.h (objc_types_compatible_p): Remove prototype.
        (OCTI_UNUSED_LIST, unused_list): Remove slot.
        * objc-lang.c (LANG_HOOKS_TYPES_COMPATIBLE_P): Remove.

From-SVN: r100123