[Performance]: SmallElementLocation optimisation doesn't actually do anything

[drewnoakes]

In the construction model, each element stores its location in the source file in an ElementLocation instance.

There are two implementations of this abstract base class: SmallElementLocation and RegularElementLocation, storing line/column data using ushort and int respectively.

The rationale here is that most values are small (< 0xFFF) and so using different storage sizes in different cases can reduce memory footprint.

However, the CLR will align the fields of this class to four-byte boundaries on most architectures for performance reasons. Therefore the optimisation in SmallElementLocation is unlikely to have any effect.

The padding/alignment can be verified here.

[drewnoakes]

My analysis was incorrect and the object layout does in fact work as intended.