I've comitted the attached patch (approved by fche)  which addresses a 
problem when building sid with recent gcc compilers. The problem is that

    this->trace_stream << endl;

does not call

   template <typename T>
    basic_cpu::cpu_trace_stream& operator<< 
(basic_cpu::cpu_trace_stream& s, T t)

as expected. As a result, sid's tracing output comes out all on one line 
when tracing is to cout. The patch defines a new method of 
basic_cpu::cpu_trace_stream which can be explicitely called to avoid the 
ambiguity.

The patch also changes an unnecessary dynamic_cast to a static_cast. 
Something we noticed while investigating.

Dave