Yes, I agree with you on this, Anatoly. As we know we'll eventually
have to move out the EE* register and bit names back into each
individual ioXXX.h file, it's really the time to do it now. Then,
embrace the existing definitions in avr/io.h within an #if defined
__COMPILING_AVR_LIBC__, and the status quo will be maintained. (No
need to check for the __AVR_device__ macros, as the macro
__COMPILING_AVR_LIBC__ is only ever supposed to be set within
avr-libc's compilation process, and then we know there's no -mmcu
option in effect.)
Are you willing to do that?