Create fewer unnecessary lists

pkg/analyzer/lib/src/generated/java_core.dart

 library java.core;
 
 final Stopwatch nanoTimeStopwatch = new Stopwatch();
 
 const int LONG_MAX_VALUE = 0x7fffffffffffffff;
 
 class JavaSystem {
   static int currentTimeMillis() {
     return (new DateTime.now()).millisecondsSinceEpoch;
   }
@@ skipping 402 matching lines @@
   return formatList(pattern, [arg0, arg1, arg2, arg3, arg4, arg5, arg6, arg7]);
 }
 
 /**
  * Inserts the given [args] into [pattern].
  *
  *     format('Hello, {0}!', ['John']) = 'Hello, John!'
  *     format('{0} are you {1}ing?', ['How', 'do']) = 'How are you doing?'
  *     format('{0} are you {1}ing?', ['What', 'read']) = 'What are you reading?'
  */
-String formatList(String pattern, List args) {
+String formatList(String pattern, List<Object> arguments) {
+  if (arguments == null || arguments.isEmpty) {
+    return pattern;
+  }
   return pattern.replaceAllMapped(new RegExp(r'\{(\d+)\}'), (match) {
     String indexStr = match.group(1);
     int index = int.parse(indexStr);
-    var arg = args[index];
+    Object arg = arguments[index];
     return arg != null ? arg.toString() : null;
   });
 }