Import AVR implementation for print(F())

Author: facchinm

Diff for: api/Print.cpp

@@ -38,7 +38,19 @@ size_t Print::write(const uint8_t *buffer, size_t size)
 
 size_t Print::print(const __FlashStringHelper *ifsh)
 {
+#if defined(__AVR__)
+  PGM_P p = reinterpret_cast<PGM_P>(ifsh);
+  size_t n = 0;
+  while (1) {
+    unsigned char c = pgm_read_byte(p++);
+    if (c == 0) break;
+    if (write(c)) n++;
+    else break;
+  }
+  return n;
+#else
   return print(reinterpret_cast<const char *>(ifsh));
+#endif
 }
 
 size_t Print::print(const String &s)