[lld] [LLD] Implement --enable-non-contiguous-regions (PR #90007)

[Daniel Thornburgh via llvm-commits]

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@@ -425,6 +426,25 @@ class InputSection : public InputSectionBase {
   template <class ELFT> void copyShtGroup(uint8_t *buf);
 };
 
+// A marker for a potential spill location for another input section. This
+// broadly acts as if it were the original section until address assignment.
+// Then it is either replaced with the real input section or removed.
+class SpillInputSection : public InputSection {
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mysterymath wrote:

I think I like `PotentialSpillSection` better than `SpillInputSection`; it's not really an `InputSection`, and it's more like a `SyntheticSection`. That also gives `potentialSpillLists` for the the tracking variable and `PotentialSpillList` for its type, which is better than `spillLists` and `SpillList`.

https://github.com/llvm/llvm-project/pull/90007