[ProfileData] Fix data racing in merging indexed profiles

There is data racing to the static variable RecordIndex in index profile reader
when merging in multiple threads. Make it a member variable in
IndexedInstrProfReader to fix this.

Differential Revision: https://reviews.llvm.org/D38431


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@314990 91177308-0d34-0410-b5e6-96231b3b80d8

lib/ProfileData/InstrProfReader.cpp

@@ -733,8 +733,6 @@ Error IndexedInstrProfReader::getFunctionCounts(StringRef FuncName,
 }
 
 Error IndexedInstrProfReader::readNextRecord(NamedInstrProfRecord &Record) {
-  static unsigned RecordIndex = 0;
-
   ArrayRef<NamedInstrProfRecord> Data;
 
   Error E = Index->getRecords(Data);