Add emulation for AVR util/parity.h

teensy3/util/parity.h

+#ifndef _UTIL_PARITY_H_
+#define _UTIL_PARITY_H_
+
+static inline uint8_t parity_even_bit(uint8_t x) __attribute__((pure, always_inline, unused));
+static inline uint8_t parity_even_bit(uint8_t x)
+{
+	x ^= x >> 1;
+	x ^= x >> 2;
+	x ^= x >> 4;
+	return x & 1;
+}
+
+#endif