[llvm] [memprof] Add YAML read/write support to llvm-profdata (PR #118915)

[Teresa Johnson via llvm-commits]

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@@ -213,6 +213,21 @@ class RawMemProfReader final : public MemProfReader {
 class YAMLMemProfReader final : public MemProfReader {
 public:
   YAMLMemProfReader() = default;
+
+  // Return true if the \p DataBuffer starts with magic bytes indicating it is
+  // a raw binary memprof profile.
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teresajohnson wrote:

Is the use of magic bytes and "raw binary memprof profile" here and below correct? This sounds like we're talking about an actual raw binary format not the Yaml version.

https://github.com/llvm/llvm-project/pull/118915