This centralizes the placeholder type error reporting in one location, but it also exposes the granularity at which we convert things from hir to ty more. E.g. previously infer types in where bounds were errored together with the function signature, but now they are independent.
```
error[E0610]: `{integer}` is a primitive type and therefore doesn't have fields
--> $DIR/attempted-access-non-fatal.rs:7:15
|
LL | let _ = 2.l;
| ^
|
help: if intended to be a floating point literal, consider adding a `0` after the period and a `f64` suffix
|
LL - let _ = 2.l;
LL + let _ = 2.0f64;
|
```