enable_tracing

Enable step tracing
     trace_level - what kind of trace to modify
     enable      - 0: turn off, 1: turn on
Returns: success

success enable_tracing(long trace_level, long enable);

#define TRACE_STEP 0x0  // lowest level trace. trace buffers are not maintained
#define TRACE_INSN 0x1  // instruction level trace
#define TRACE_FUNC 0x2  // function level trace (calls & rets)
#define TRACE_BBLK 0x4  // basic block level trace