fix: fixed Impl display to show trait generic args

[benodiwal]

Closes #21196

[ChayimFriedman2]

I don't want to use trait_ref() as it will print the hir-ty representation but I prefer the hir-def one, is there a reason you don't use target_trait as I suggested on the issue?

[benodiwal]

I don't want to use trait_ref() as it will print the hir-ty representation but I prefer the hir-def one, is there a reason you don't use target_trait as I suggested on the issue?

Thanks! I initially used trait_ref() as it was the obvious high-level API with an existing HirDisplay impl. But you're right that target_trait is better here since it uses the hir-def representation rather than going through hir-ty type resolution which is more appropriate for display purposes and consistent with the rest of the function. There is not any sepcific reason I used this approach, I just thought you have suggested one way to do it and its not rigid.
I have updated it now!

[ChayimFriedman2]

Thanks!