Using forEach to avoid Iterator allocation

Author: dougqh

dd-trace-core/src/main/java/datadog/trace/core/CoreTracer.java

@@ -1230,9 +1230,10 @@ void write(final List<DDSpan> trace) {
 
     // run early tag postprocessors before publishing to the metrics writer since peer / base
     // service are needed
-    for (DDSpan span : writtenTrace) {
-      span.processServiceTags();
-    }
+    
+    // DQH - Using forEach avoids ArrayList$Iter allocation
+    writtenTrace.forEach(DDSpan::processServiceTags);
+    
     boolean forceKeep = metricsAggregator.publish(writtenTrace);
 
     TraceCollector traceCollector = writtenTrace.get(0).context().getTraceCollector();