[llvm] [llvm-profdata] Use simple enum for error checking in Sample Profile Reader (PR #67453)

[Hongtao Yu via llvm-commits]

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@@ -604,48 +604,52 @@ class SampleProfileReaderBinary : public SampleProfileReader {
   /// EC is set.
   ///
   /// \returns the read value.
-  template <typename T> ErrorOr<T> readNumber();
+  template <typename T> sampleprof_error readNumber(T &Result);
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htyu wrote:

I only see changes to the function declaration but not int he function implementation. Am I missing anything or it'll be included in a separate PR?

I also wonder how much end-to-end performance improvement did you see in your experiments? The `ErrorOr` usage is quite handy and prevailing in the code base.  

https://github.com/llvm/llvm-project/pull/67453