Set the llvm standard output stream to be unbuffered. (#678)

This is particularly useful for the simulation when invokved
inside Eclipse.  Otherwise, you won't see the robot starting
message.

hal/src/main/native/sim/HAL.cpp

@@ -7,6 +7,8 @@
 
 #include "HAL/HAL.h"
 
+#include <llvm/raw_ostream.h>
+
 #include "ErrorsInternal.h"
 #include "HAL/DriverStation.h"
 #include "HAL/Errors.h"
@@ -204,6 +206,7 @@ HAL_Bool HAL_Initialize(int32_t timeout, int32_t mode) {
   // Second check in case another thread was waiting
   if (initialized) return true;
 
+  llvm::outs().SetUnbuffered();
   if (HAL_LoadExtensions() < 0) return false;
   hal::RestartTiming();
   HAL_InitializeDriverStation();