Generate IR definitions by annotation processor

[Akirathan]

In the current definition of the IR, there is a hierarchy of traits and case classes. Majority of the code inside these case classes is highly repetitive.

There is PoC in #11267 that already contains the definitions of the annotations and the processor.

The ultimate goal of this task is to:

• Replace the Scala trait hierarchy with Java interface hierarchy
• Replace Scala case classes by automatically generated Java classes.
• Ensure that all the changes are compatible, that is, all the code inside runtime-compiler that manipulates with IR either stays completely the same, or is changed just cosmetically, like adding few more named arguments to a method call that previously had a default value.