[llvm] [VPlan] Add VPInst::getNumOperandsForOpcode, use to verify in ctor (NFC) (PR #142284)

[via llvm-commits]

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@@ -706,13 +706,15 @@ TEST_F(VPBasicBlockTest, reassociateBlocks) {
 
 #if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP)
 TEST_F(VPBasicBlockTest, print) {
-  VPInstruction *TC = new VPInstruction(Instruction::Add, {});
+  VPInstruction *TC = new VPInstruction(Instruction::PHI, {});
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ayalz wrote:

To escape num operands check?
Considered scalar, w/o operands.

https://github.com/llvm/llvm-project/pull/142284