[clang-format] Handle object instansiation in if-statements

Before this patch code like this:

```
if (Class* obj{getObject()}) { }
```

would be mis-formated since the * would be annotated as a
binaryoperator.

This patch changes the * to become a PointerOrReference instead
and fixes the formatting issues.

Reviewed By: HazardyKnusperkeks

Differential Revision: https://reviews.llvm.org/D137327