Various functions taking a `TyCtxt` and a `Span` should be taking a `TyCtxtAt`

[oli-obk]

One example is the is_sized method on Ty. Internally it creates a tcx.at(span), when it could simply be taking exactly that TyCtxtAt as an argument. In miri I had to write ty.is_sized(tcx.tcx, param_env, tcx.span) which just feels a little riddiculous (taking apart the TyCtxtAt, just to have the method construct it back).

There's probably many other similar methods and functions that should be taking a TyCtxtAt

[PramodBisht]

Can I take this one if no one is working on that ?

[oli-obk]

@PramodBisht it's all yours!