always epicsThreadStackBig

On RTEMS at least, c++ code needs the largest
standard stack frame size.

src/misc/pv/thread.h

@@ -158,7 +158,7 @@ public:
     Thread(std::string name,
            ThreadPriority priority,
            Runnable *runnable,
-           epicsThreadStackSizeClass stkcls=epicsThreadStackSmall);
+           epicsThreadStackSizeClass stkcls=epicsThreadStackBig);
 
     /**
      * 

src/misc/reftrack.cpp

@@ -223,7 +223,7 @@ void RefMonitor::start(double period)
     impl->period = period;
     impl->worker.reset(new epicsThread(*impl,
                                        "RefMonitor",
-                                       epicsThreadGetStackSize(epicsThreadStackSmall),
+                                       epicsThreadGetStackSize(epicsThreadStackBig),
                                        epicsThreadPriorityMin));
     impl->worker->start();
 }

src/misc/thread.cpp

@@ -52,7 +52,7 @@ void Thread::Config::x_setdefault()
     this->p_prio = epicsThreadPriorityLow;
     this->p_autostart = true;
     this->p_runner = NULL;
-    (*this).stack(epicsThreadStackSmall);
+    (*this).stack(epicsThreadStackBig);
 }
 
 size_t Thread::num_instances;