Include Compat header only if C++

Author: facchinm

Diff for: api/ArduinoAPI.h

@@ -53,7 +53,9 @@
 // Misc Arduino core functions
 #include "Common.h"
 
+#ifdef __cplusplus
 // Compatibility layer for older code
 #include "Compat.h"
+#endif
 
 #endif