rustc overflow with size_of::<Self> constraint

I want to do things with a type level representation of my type's size, i.e. U<{core::mem::size_of::<Self>()}> in the below code. This requires a [(); core::mem::size_of::<Self>()]: bound everywhere, which breaks the compiler.

This is especially annoying because IMO [(); core::mem::size_of::<T>()]: should come for free for all T

#![feature(associated_type_defaults)]
#![feature(generic_const_exprs)]

struct U<const N: usize>;

trait Foo: Sized where [(); core::mem::size_of::<Self>()]:
{
    type MyU = U<{core::mem::size_of::<Self>()}>;
}

impl<T: Sized> Foo for T 
where 
  [(); core::mem::size_of::<Self>()]:,
  Self::MyU:
{}

https://play.rust-lang.org/?version=nightly&mode=debug&edition=2021&gist=8352f18917259811c1e72a8fd153c684

This simplified version also breaks

#![feature(generic_const_exprs)]

struct U<const N: usize>;

trait Foo: Sized where [(); core::mem::size_of::<Self>()]:
{
    type MyU;
}

impl<T: Sized> Foo for T 
where 
  [(); core::mem::size_of::<Self>()]:,
  Self::MyU:
{}

https://play.rust-lang.org/?version=nightly&mode=debug&edition=2021&gist=a224e122810fcfbb34c69b56a067ce82

Start by reproducing both linked Rust Playground examples on nightly and recording the overflow diagnostics. Then trace the compiler's handling of the [(); core::mem::size_of::<Self>()]: bounds and generic const expressions; done means these examples no longer overflow while preserving the intended validity checks.