[llvm] [Instrumentor] Add Instrumentor pass (PR #138958)

[Matt Arsenault via llvm-commits]

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@@ -0,0 +1,645 @@
+//===-- Instrumentor.cpp - Highly configurable instrumentation pass -------===//
+//
+// 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
+//
+//===----------------------------------------------------------------------===//
+//
+//===----------------------------------------------------------------------===//
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arsenm wrote:

```suggestion
```

https://github.com/llvm/llvm-project/pull/138958