Rename analyzer-experimental to analyzer_experimental.

pkg/analyzer_experimental/lib/src/generated/java_engine_io.dart

 library java.engine.io;
 
 import "dart:io";
 import "java_io.dart";
 
 
 class OSUtilities {
   static bool isWindows() => Platform.operatingSystem == 'windows';
   static bool isMac() => Platform.operatingSystem == 'macos';
 }
 
 class FileUtilities2 {
   static JavaFile createFile(String path) => new JavaFile(path);
 }