Optimistically placing this in 9.0 milestone.

We should unify the reflection stack with the stack shared with Mono/CoreCLR-JIT.

Things we can enable once that's done:

• Roll back Emit less metadata for not-reflection-visible types #91660. Instead of doing the extra analysis, we should no longer need to generate any metadata for unconstructed MethodTables (basically roll back EETypeNode/ConstructedEETypeNode/etc. to how it looked before Get rid of reflection blocked types #85810 that triggered the bugfix)
• Preinitialization of System.RuntimeType instances and related RyuJIT features that can directly reference System.RuntimeType addresses.
• Allocate lazily created System.RuntimeType instances on frozen heap