builtins.c (expand_builtin_saveregs): Remove static, remove exp and ignore arguments, bail if no EXPAND_BUILTIN_SAVEREGS.

        * builtins.c (expand_builtin_saveregs): Remove static, remove exp
        and ignore arguments, bail if no EXPAND_BUILTIN_SAVEREGS.
        (expand_builtin_next_arg): Accept ARGLIST not EXP.
        (stabilize_va_list): New function.
        (std_expand_builtin_va_start): New function.
        (expand_builtin_va_start): New function.
        (get_varargs_alias_set): New function.
        (std_expand_builtin_va_arg): New function.
        (expand_builtin_va_arg): New function.
        (expand_builtin_va_end): New function.
        (expand_builtin_va_copy): New function.
        (expand_builtin): Call them.
        * c-common.c (c_common_nodes_and_builtins): Build __builtin_va_list,
        __builtin_{varargs_start,stdarg_start,end,copy}.
        (build_va_arg): New function.
        * c-common.h (CTI_PTR_TYPE, ptr_type_node): Delete.
        (build_va_arg): Declare.
        * c-decl.c (ptr_type_node, va_list_type_node): New.
        * c-parse.gperf (__builtin_va_arg): New.
        * c-parse.in (VA_ARG): New token.
        (unary_expr): Recognize it.
        * expr.c (expand_expr): Expand VA_ARG_EXPR.
        * expr.h (std_expand_builtin_va_start): Declare.
        (std_expand_builtin_va_arg): Declare.
        (expand_builtin_va_arg): Declare.
        (get_varargs_alias_set): Declare.
        * tree.def (VA_ARG_EXPR): New.
        * tree.h (BUILT_IN_VARARGS_START): New.
        (BUILT_IN_STDARG_START, BUILT_IN_VA_END): New.
        (ptr_type_node, va_list_type_node): Declare.
        * tm.texi (EXPAND_BUILTIN_SAVEREGS): Kill unused ARGLIST argument.
        * m32r.h (EXPAND_BUILTIN_SAVEREGS): Likewise.
        * m88k.h, m88k.c: Likewise.
        * mn10300.h, mn10300.c: Likewise.
        * pa.h, pa.c: Likewise.
        * rs6000.h, rs6000.c: Likewise.
        * sh.h, sh.c: Likewise.
        * sparc.h, sparc.c: Likewise.

        * emit-rtl.c (operand_subword): Copy alias set.
        (change_address): Likewise.

From-SVN: r28243