chore(build): add experimental Dart build that uses DDC for code analysis

gulpfile.js

@@ -243,6 +243,12 @@ gulp.task('build/analyze.dart', dartanalyzer(gulp, gulpPlugins, {
   command: DART_SDK.ANALYZER
 }));
 
+gulp.task('build/analyze.ddc.dart', dartanalyzer(gulp, gulpPlugins, {
+  dest: CONFIG.dest.dart,
+  command: DART_SDK.ANALYZER,
+  use_ddc: true
+}));
+
 // ------------
 // pubbuild
 // WARNING: this task is very slow (~15m as of July 2015)