[AVR] Raise and link to a tracking issue for the `avr-interrupt` calling convention
[AVR] Raise and link to a tracking issue for the `avr-interrupt` calling convention

Also fix the order of the feature gate to fix the tidy errors.

graydon/rust,graydon/rust,graydon/rust,graydon/rust,aidancully/rust,aidancully/rust,aidancully/rust,graydon/rust,graydon/rust,aidancully/rust,aidancully/rust,aidancully/rust