[llvm] [SandboxIR] Boilerplate code (PR #95814)

[Arthur Eubanks via llvm-commits]

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@@ -0,0 +1,154 @@
+//===- SandboxIR.h ----------------------------------------------*- C++ -*-===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+//
+// Sandbox IR is a lightweight overlay transactional IR on top of LLVM IR.
+// Features:
+// - You can save/rollback the state of the IR at any time.
+// - Any changes made to Sandbox IR will automatically update the underlying
+//   LLVM IR so both IRs are always in sync.
+// - Feels like LLVM IR, similar API.
+//
+// SandboxIR forms a class hierarcy that resembles that of LLVM IR
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aeubanks wrote:

nit: hierarchy

https://github.com/llvm/llvm-project/pull/95814