[llvm] Introduce CovMap in ObjectYAML (PR #127432)

[Jessica Paquette via llvm-commits]

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@@ -0,0 +1,390 @@
+//===- CovMap.h - ObjectYAML Interface for coverage map ---------*- 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
+//
+//===----------------------------------------------------------------------===//
+//
+// - llvm::coverage::yaml
+//
+//   Describes binary file formats and YAML structures of coverage map.
+//
+// - llvm::yaml
+//
+//   Attachments for YAMLTraits.
+//
+// - llvm::covmap
+//
+//   Provides YAML encoder and decoder for coverage map.
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ornata wrote:

would it be possible to do only the encoder or decoder first in this patch, and then in another patch, do the other one?

e.g.

- patch 1: add ability to encode
- patch 2: add ability to decode
- patch 3: add support for covmap-raw
- patch 4: add support for covmap-dloc 

https://github.com/llvm/llvm-project/pull/127432