[llvm] [VPlan] Type VP(Recipe|Block)Ty SubclassID (NFC) (PR #209132)

[Ramkumar Ramachandra via llvm-commits]

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@@ -383,6 +377,13 @@ class LLVM_ABI_FOR_TEST VPBlockBase {
   /// the cloned recipes, including all blocks in the single-entry single-exit
   /// region for VPRegionBlocks.
   virtual VPBlockBase *clone() = 0;
+
+private:
+  const VPBlockTy SubclassID; ///< Subclass identifier (for isa/dyn_cast).
+
+protected:
+  VPBlockBase(const VPBlockTy SC, const std::string &N)
+      : Name(N), SubclassID(SC) {}
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artagnon wrote:

... because it needs to see the definition of VPBlockTy?

https://github.com/llvm/llvm-project/pull/209132