re PR bootstrap/44048 (building without C++ enabled fails)

re PR bootstrap/44048 (building without C++ enabled fails)

	PR bootstrap/44048
	PR target/44099
gcc/cp:
	* cp-tree.def (NULLPTR_TYPE): Remove.
	* cp-tree.h (NULLPTR_TYPE_P): New.
	(SCALAR_TYPE_P): Use it.
	(nullptr_type_node): New.
	(cp_tree_index): Add CPTI_NULLPTR_TYPE.
	* decl.c (cxx_init_decl_processing): Call record_builtin_type on
	nullptr_type_node.
	* cvt.c (ocp_convert): Use NULLPTR_TYPE_P instead of NULLPTR_TYPE.
	* cxx-pretty-print.c (pp_cxx_constant): Likewise.
	* error.c (dump_type, dump_type_prefix, dump_type_suffix): Likewise.
	* mangle.c (write_type): Likewise.
	* name-lookup.c (arg_assoc_type): Likewise.
	* typeck.c (build_reinterpret_cast_1): Likewise.
	* rtti.c (typeinfo_in_lib_p): Likewise.
	(emit_support_tinfos): Remove local nullptr_type_node.
gcc:
	* dbxout.c (dbxout_type): Remove NULLPTR_TYPE handling.
	* sdbout.c (plain_type_1): Likewise.
	* dwarf2out.c (is_base_type): Likewise.
	(gen_type_die_with_usage): Likewise.  Generate
	DW_TAG_unspecified_type for any LANG_TYPE.

From-SVN: r159350