Merge pull request chipKIT32#346 from EmbeddedMan/master

Fix for issue chipKIT32#345 : serialEventRun compiler warning in main.cpp

Author: EmbeddedMan

pic32/cores/pic32/HardwareSerial.h

@@ -342,7 +342,7 @@ class USBSerial : public Stream
         #endif
 #endif
 
-void serialEventRun();
+extern void serialEventRun(void) __attribute__((weak));
 
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