AOT generates a raw type for a generic type with nested unresolved generics

[snicoll]

Initially reported by @odrotbohm on Spring Restbucks.

There is a check in code generator for ResolvableType:

spring-framework/spring-core/src/main/java/org/springframework/aot/generate/ValueCodeGeneratorDelegates.java

Line 334 in ce49354

if (resolvableType.hasGenerics() && !resolvableType.hasUnresolvableGenerics()) {

There have been several refinements in the core container and its type detection algorithm. I suspect that it's smarter at finding out about such unresolved generics in nested types. It unfortunately means we're taking the wrong decision now, writing the raw type instead of the type with it's top-level generic signature.

[snicoll]

The check was introduced by #29454