[clang] [clang][modules] Remove preloaded SLocEntries from PCM files (PR #66962)

[Jan Svoboda via cfe-commits]

jansvoboda11 wrote:

> Thanks for iterating! I find the current implementation much clearer.

Thanks for your patience!

> The only thing I might quibble about is the "child" vs. "parent" terminology you changed: I think it's fairly ambiguous either way, because the node is the "child" from the perspective of a top-down include hierarchy, but it's the "parent" from the perspective of the bottom-up search. You could maybe change it to IncludedFile or something, but I don't feel very strongly about it. Child is no worse than parent so if you prefer child I don't think you need to change it.

I understand. My problem with using "parent" here is that we're using "parent" just a couple lines above to describe the opposite relationship:

```
// - one loc is a parent of the other (we consider the parent as "first")
```

So I believe framing all the relationships in terms of the top-down include/expansion hierarchy makes more sense than mixing them up with the bottom-up tree walk.

https://github.com/llvm/llvm-project/pull/66962