[llvm] [PGO] Add support for writing previous indexed format (PR #84505)

[Snehasish Kumar via llvm-commits]

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@@ -68,10 +68,18 @@ class InstrProfWriter {
   // Use raw pointer here for the incomplete type object.
   InstrProfRecordWriterTrait *InfoObj;
 
+  // Temporary support for writing the previous version of the format, to enable
+  // some forward compaitibility. Currently this suppresses the writing of the
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snehasish wrote:

typo: compatibility 

https://github.com/llvm/llvm-project/pull/84505