[display] find references doesn't find enum constructor patterns

```haxe
import haxe.macro.Expr.ExprDef;

class Main {
public static function main() {
switch ((null:ExprDef)) {
case EConst(c):
case _:
}
}
}
```


When invoking find references on the `EConst` here, it does find two _instantiations_ in `Compiler.hx`, but it seems unable to find references of enum constructors in _patterns_ (e.g. the one in the `Main.hx` file itself, and there's others in std like in `ExprTools`, `haxe.macro.Printer`...):