(NULLT): Deleted; all uses changed to NULL_TREE.
(get_{static,object}_reference, objc_add_static_instance):
Use push_obstacks instead of saving obstacks manually.
(build_{selector,class}_reference_decl): Likewise.
(build_objc_string_decl, build_protocol_reference): Likewise.
(comp_{method,proto}_with_proto): Likewise.
(create_builtin_decl, synth_module_prologue): Set DECL_ARTIFICIAL for internal
objects.
(build_{selector,class}_reference_decl, add_objc_decls): Likewise.
(generate_objc_symtab_decl, build_module_descriptor): Likewise.
(build_protocol_reference): Likewise.
(build_objc_string_decl, synch_forward_declarations): Likewise.
Delete call to end_temporary_allocation.
(generate_static_references, generate_strings): Likewise.
(build_selector_translation_table, generate_category): Likewise.
(generate_{ivars,protocol}_list, build_protocol_reference): Likewise.
(build_objc_string_object): If next_runtime, put everything in
permanent obstack.
(objc_add_static_instance): Use build_decl instead of start_decl
and finish_decl_top_level.
(build_{class_reference,objc_string}_decl): Clear DECL_CONTEXT.
(start_class): Exit with FATAL_EXIT_CODE, not 1.
(add_objc_decls): Don't set DECL_IN_SYSTEM_HEADER.

From-SVN: r9764