Re: [v3] Avoid -Wall warnings in the testsuite

[Paolo Carlini]

... actually, there are also bogus "statement has no effect" warnings 
for line 1321 of ext/pb_ds/detail/pat_trie_/pat_trie_base.hpp which also 
seem bogus:

    PB_DS_CLASS_T_DEC
    typename PB_DS_CLASS_C_DEC::size_type
    PB_DS_CLASS_C_DEC::
    get_begin_pos() const
    {
      size_type i = 0;
      for (i; i < arr_size && m_a_p_children[i] == 0; ++i) // here
    ;
      return i;
    }
Paolo.