[llvm] [CodeGen] Port DwarfEHPrepare to new pass manager (PR #72500)

[via llvm-commits]

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@@ -0,0 +1,37 @@
+//===------------------- llvm/CodeGen/DwarfEHPrepare.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
+//
+//===----------------------------------------------------------------------===//
+//
+// This pass mulches exception handling code into a form adapted to code
+// generation. Required if using dwarf exception handling.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_CODEGEN_DWARFEHPREPARE_H
+#define LLVM_CODEGEN_DWARFEHPREPARE_H
+
+#include "llvm/IR/PassManager.h"
+
+namespace llvm {
+
+class TargetMachine;
+
+class DwarfEHPreparePass : public PassInfoMixin<DwarfEHPreparePass> {
+  const TargetMachine *TM;
+  CodeGenOptLevel OptLevel;
+
+public:
+  explicit DwarfEHPreparePass(
+      const TargetMachine *TM_,
+      CodeGenOptLevel OptLevel_ = CodeGenOptLevel::Default)
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paperchalice wrote:

Another inconsistence, the `CodeGenOptLevel` in `opt` is controlled by 
https://github.com/llvm/llvm-project/blob/5d59e97e883445f36e99d4b9600330ac4a631565/llvm/tools/opt/opt.cpp#L178-L180
https://github.com/llvm/llvm-project/blob/5d59e97e883445f36e99d4b9600330ac4a631565/llvm/tools/opt/opt.cpp#L641-L643
So, the default value is `CodeGenOptLevel::None` in `opt`.

https://github.com/llvm/llvm-project/pull/72500