Use coroutines for avr-gcc

[Wilhelm Meier <wilhelm.meier@hs-kl.de>]

I tried to use coroutines with avr-gcc (13.0.0) for the AVR target. I 
managed to include the coroutine-header and to write a very simple 
generator using the example from cppreference.

It compiles well, but then I get undefined symbols:

1) new and delete operator-functions
2) f(f()::f().Frame*)

Therefore two question arise here:

a) is it possible to use coroutines without head-allocation? E.g. define 
some global storage for the state of the coroutine?
b) if a) can be fullfilled, what is 2) supposed to do?

Thanks for any hints,
  Wilhelm