Merge pull request stm32duino#171 from fpistm/gcc_check

Added checking gcc version

Author: fpistm

Diff for: cores/arduino/Arduino.h

@@ -20,6 +20,15 @@
 #ifndef Arduino_h
 #define Arduino_h
 
+#ifndef GCC_VERSION
+#define GCC_VERSION (__GNUC__ * 10000 \
+                     + __GNUC_MINOR__ * 100 \
+                     + __GNUC_PATCHLEVEL__)
+#endif
+#if GCC_VERSION < 60300
+#error "GCC version 6.3 or higher is required"
+#endif
+
 #include "wiring.h"
 
 /* sketch */