Don't set didStopEarly after the final invocation.

Author: timcassell

src/BenchmarkDotNet/Engines/EngineJitStage.cs

@@ -89,23 +89,30 @@ private IEnumerator<IterationData> EnumerateIterations()
             MaybeSleep(JitInfo.TieredDelay);
 
             // Attempt to promote methods to tier1, but don't spend too much time in jit stage.
+            int tierCount = JitInfo.IsDPGO ? 2 : 1;
+            ++iterationIndex;
+
             StartedClock startedClock = parameters.TargetJob.ResolveValue(InfrastructureMode.ClockCharacteristic, parameters.Resolver).Start();
+            yield return GetOverheadIterationData();
+            yield return GetWorkloadIterationData();
 
-            int tierCount = JitInfo.IsDPGO ? 2 : 1;
-            for (int i = 0; i < tierCount; ++i)
+            int callCount = JitInfo.TieredCallCountThreshold - 1;
+            for (; tierCount >= 0; --tierCount)
             {
-                for (int j = 0; j < JitInfo.TieredCallCountThreshold; ++j)
+                for (; callCount >= 0; --callCount)
                 {
-                    ++iterationIndex;
-                    yield return GetOverheadIterationData();
-                    yield return GetWorkloadIterationData();
-
                     if (startedClock.GetElapsed().GetTimeValue() >= MaxTieringTime)
                     {
                         didStopEarly = true;
                         yield break;
                     }
+
+                    ++iterationIndex;
+                    yield return GetOverheadIterationData();
+                    yield return GetWorkloadIterationData();
                 }
+
+                callCount = JitInfo.TieredCallCountThreshold;
             }
         }