chore: correctly updates the compiled flag (#5767)

scripts/gulpfiles/build_tasks.js

@@ -457,6 +457,7 @@ function compile(options) {
     language_out: 'ECMASCRIPT5_STRICT',
     rewrite_polyfills: true,
     hide_warnings_for: 'node_modules',
+    define: ['COMPILED=true'],
     externs: ['./externs/svg-externs.js'],
   };
   if (argv.debug || argv.strict) {