[llvm] [SandboxIR] Implement AllocaInst (PR #102027)

[via llvm-commits]

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@@ -1393,6 +1396,108 @@ class GetElementPtrInst final : public Instruction {
 #endif
 };
 
+class AllocaInst final : public UnaryInstruction {
+  Use getOperandUseInternal(unsigned OpIdx, bool Verify) const final {
+    return getOperandUseDefault(OpIdx, Verify);
+  }
+  SmallVector<llvm::Instruction *, 1> getLLVMInstrs() const final {
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vporpo wrote:

I think that would also help with a couple more functions that repeat in a similar way, like `getOpreandUseInteral()`, `getUseOperandNo()` and `getNumOfIRInstrs()`.

I will upload a separate patch for this.

https://github.com/llvm/llvm-project/pull/102027