[lld] [ELF] Orphan placement: prefer the last similar section when its rank <= orphan's rank (PR #94099)

[Peter Smith via llvm-commits]

================
@@ -935,14 +935,18 @@ findOrphanPos(SmallVectorImpl<SectionCommand *>::iterator b,
       return i;
   }
 
-  // Find the first element that has as close a rank as possible.
   if (b == e)
     return e;
+  // Select the most similar output section. In case of ties, select the first
+  // section with a rank > the orphan's rank, or the last one with a rank <= the
+  // orphan's rank.
   int proximity = getRankProximity(sec, *b);
   auto i = b;
   for (auto j = b; ++j != e;) {
-    int p = getRankProximity(sec, *j);
-    if (p > proximity) {
+    auto p = getRankProximity(sec, *j);
+    if (p > proximity ||
----------------
smithp35 wrote:

I'm trying to match this up with the comment:
```
In case of ties, select the first section with a rank > the orphan's rank, or the last one with a rank <= the orphan's rank.
```
I can see the "or the last one with a rank <= orphan's rank" explicit in the condition. I think the first part is implicit because we already have a section selected "first section" and we don't update it.

Not entirely sure how to make this clearer though. Perhaps rewording the original comment to:
```
In the event of proximity ties, we select the first section, unless a later section with the same proximity has a rank <= the orphan's rank.
```

https://github.com/llvm/llvm-project/pull/94099