typeck (type_for_mode): Only return TItype nodes when HOST_BITS_PER_WIDE_INT is ...

typeck (type_for_mode): Only return TItype nodes when HOST_BITS_PER_WIDE_INT is >= 64 bits.

        * typeck (type_for_mode): Only return TItype nodes when
        HOST_BITS_PER_WIDE_INT is >= 64 bits.
        (type_for_size): Similarly.
        * decl.c (intTI_type_node, unsigned_intTI_type_node): Only declare
        when HOST_BITS_PER_WIDE_INT is >= 64 bits.
        (init_decl_processing): Only create TItype nodes when
        HOST_BITS_PER_WIDE_INT is >= 64 bits.

From-SVN: r22914