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

[Teresa Johnson via llvm-commits]

================
@@ -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
----------------
teresajohnson wrote:

done

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