Allow the bit/res/set bit index to be determined at link time (#1654)

This increments the object file revision number from 11 to 12
since it adds a new `RPN_BIT_INDEX` command.

include/asm/rpn.hpp

@@ -51,6 +51,7 @@ struct Expression {
 
 	bool makeCheckHRAM();
 	void makeCheckRST();
+	void makeCheckBitIndex(uint8_t mask);
 
 	void checkNBit(uint8_t n) const;