Add helper for equivlent of Types.asMemeberOf

[evant]

When writing an annotation processor you can use Types.asMemeberOf() to resolve the concrete type of a method based on the enclosing class. Ex if you had:

interface GenericInterface<T> {
  bar(): T
}

abstract class Foo : GenericInterface<String> {
}

you could get that bar() in the context of Foo returns String.

[neetopia]

We have this in our reference.md for asMemeberOf()
asMemberOf | ksClassDeclaration.typeArguments + ksClassDeclaration.asType

does this serve your purpose? It looks what you need is a type substitution for the type parameter of bar().

[ting-yuan]

Besides using the type directly, I guess Types.asMemberOf() is also useful on deducing the type arguments. This can be expensive potentially as it needs to resolve all the way up to the supertype that contains the member in question.

Let's make this P3 (nice to have) for now.

[yigit]

FYI I started working on this: https://github.com/yigit/ksp/tree/as-member-of based on the version in Room.
No promises on the timeline though :)