[lld] [ELF] Move target-specific synthetic sections into Arch/ files (PR #184057)

[Fangrui Song via llvm-commits]

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@@ -32,6 +32,7 @@ class TargetInfo {
 public:
   TargetInfo(Ctx &ctx) : ctx(ctx) {}
   virtual uint32_t calcEFlags() const { return 0; }
+  virtual void initTargetSections() {}
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MaskRay wrote:

Thanks for the suggestion. Renamed to `TargetInfo::initTargetSpecificSections`. I've used a concise comment that omits `ctx.in` and `ctx.inputSections`. That can be easily derived from the in-tree examples.

https://github.com/llvm/llvm-project/pull/184057