Rust: Speedup type inference for Trait::function() calls

[hvitved]

When resolving calls like Trait::function(...) we need to take all possible implementations of function into account, which can be a very large set.

However, with #21217:

As for calls to methods, we now also always check the Self type for calls to associated non-methods f

which means that we can strictly reduce this set up front, by only looking at implementations for types that might match the Self type inferred at the call site, similar to what we already do for method calls.

DCA

Fixes timeout on ArmchairDevelopers/Glacier.