[llvm] [NFC][MC][Decoder] Extract fixed pieces of decoder code into new header file (PR #154802)

[Craig Topper via llvm-commits]

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@@ -0,0 +1,71 @@
+//===----------------------------------------------------------------------===//
+//
+// 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
+//
+//===----------------------------------------------------------------------===//
+// Disassembler decoder helper functions.
+//===----------------------------------------------------------------------===//
+#ifndef LLVM_MC_MCDECODER_H
+#define LLVM_MC_MCDECODER_H
+
+#include "llvm/MC/MCDisassembler/MCDisassembler.h"
+#include "llvm/Support/MathExtras.h"
+#include <cassert>
+
+namespace llvm {
+class APInt;
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topperc wrote:

APInt is not mentioned elsewhere in this file.

https://github.com/llvm/llvm-project/pull/154802