[lld] [ELF] Retain .rela.dyn for PPC64 PI long-branch thunks (PR #212078)

[Fangrui Song via llvm-commits]

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@@ -1747,6 +1747,17 @@ template <class ELFT> void Writer<ELFT>::optimizeBasicBlockJumps() {
       is->trim();
 }
 
+// Sections that finalizeAddressDependentContent may add to.
+static bool mayGrowLate(Ctx &ctx, SyntheticSection *sec) {
+  if (sec != ctx.in.relaDyn.get())
+    return false;
+  // Relocations may move here from .relr.auth.dyn.
+  if (ctx.in.relrAuthDyn && ctx.in.relrAuthDyn->isNeeded())
+    return true;
+  // PPC64PILongBranchThunk adds a relative relocation for its .branch_lt entry.
+  return ctx.in.ppc64LongBranchTarget && ctx.arg.isPic;
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MaskRay wrote:

Changed. Added a --pic-thunk test.

https://github.com/llvm/llvm-project/pull/212078