Bad template resolution for operator overloads

[Fletterio]

Here's a godbolt showcasing the problem: https://godbolt.org/z/1j1EPbfos

As you can see in it, the templated operator() fails to resolve correctly when I is Bar<SomeCondition> for the struct Foo<Bar<SomeCondition>>. It works if you provide an explicit, non-templated version where the argument is exactly Bar<SomeCondition>, as you can see by uncommenting the commented method. Also, the problem is explicitly with operators, as the method baz resolves just fine when I is Bar<SomeCondition>. This works as one would expect in CPP: https://godbolt.org/z/efrY14hW8

This issue affects both DXIL and SPIR-V targets

[Fletterio]

In fact it's even worse: uncommenting that method disables the one where the argument is generic, so effectively you can only have one or the other, not both