Re-apply LiveInterval index dumping patch, with fixes suggested by Bill

and others.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@78003 91177308-0d34-0410-b5e6-96231b3b80d8

lib/CodeGen/LiveIntervalAnalysis.cpp

@@ -2501,3 +2501,9 @@ LiveRange LiveIntervals::addLiveRangeToEndOfBlock(unsigned reg,
   
   return LR;
 }
+
+raw_ostream &
+IntervalPrefixPrinter::operator()(raw_ostream &out,
+                                  const MachineInstr &instr) const {
+      return out << liinfo.getInstructionIndex(&instr);
+}