[lld] [ELF] Support relocatable files using CREL (PR #98115)

[Fangrui Song via llvm-commits]

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@@ -470,6 +481,11 @@ void OutputSection::writeTo(uint8_t *buf, parallel::TaskGroup &tg) {
   llvm::TimeTraceScope timeScope("Write sections", name);
   if (type == SHT_NOBITS)
     return;
+  if (type == SHT_CREL && !(flags & SHF_ALLOC)) {
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MaskRay wrote:

When `-z crel` is added for `.rela.crel` (https://github.com/MaskRay/llvm-project/tree/demo-crel), `SHF_ALLOC SHT_CREL` will be possible, so I'm inclined to keep the `!SHF_ALLOC` check.

https://github.com/llvm/llvm-project/pull/98115