Assertion `pair.second == ConcreteType(BaseType::Pointer) || pair.second == ConcreteType(BaseType::Anything)

A reduced bugreport from https://github.com/g-bauer/enzyme_playground case2.
I'd recommend to fix the SCEV issue first, since 4+ other cases run into it.
The reproducer below triggers the assertion in the title when we compile case2 with rustc. However, if I print the module right before the enzyme pass and then just run the pass through opt, standalone, then we don't trigger TA, but the SCEV bug. `LooseTypes` has no effect.

Error message:
```
rustc: /home/manuel/prog/rust-master/src/tools/enzyme/enzyme/Enzyme/TypeAnalysis/TypeTree.h:607: TypeTree TypeTree::Lookup(size_t, const llvm::DataLayout &) const: Assertion `pair.second == ConcreteType(BaseType::Pointer) || pair.second == ConcreteType(BaseType::Anything)' failed.
```
We don't create any tt in the upstream rustc at all, so that should be an enzyme bug.

[mod2.ll.txt](https://github.com/user-attachments/files/20140588/mod2.ll.txt)