[llvm] [VPlan] Add BranchOnMultiCond, use for early exit plans. (PR #172750)

[via llvm-commits]

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@@ -656,6 +659,8 @@ Value *VPInstruction::generate(VPTransformState &State) {
     applyMetadata(*Br);
     return Br;
   }
+  case VPInstruction::BranchOnTwoConds:
+    llvm_unreachable("BranchOnTwoConds should be expanded before execution");
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ayalz wrote:

nit: perhaps better to group all abstract cases together.

https://github.com/llvm/llvm-project/pull/172750