Implement modular compilation

lib/runtime/dart/_js_primitives.js

Index: lib/runtime/dart/_js_primitives.js
diff --git a/lib/runtime/dart/_js_primitives.js b/lib/runtime/dart/_js_primitives.js
deleted file mode 100644
index a7a5f8fdd0735e7177035e1b82a1035f7a729c2c..0000000000000000000000000000000000000000
--- a/lib/runtime/dart/_js_primitives.js
+++ /dev/null
@@ -1,29 +0,0 @@
-dart_library.library('dart/_js_primitives', null, /* Imports */[
-  'dart/_runtime',
-  'dart/core'
-], /* Lazy imports */[
-], function(exports, dart, core) {
-  'use strict';
-  let dartx = dart.dartx;
-  function printString(string) {
-    if (typeof dartPrint == "function") {
-      dartPrint(string);
-      return;
-    }
-    if (typeof console == "object" && typeof console.log != "undefined") {
-      console.log(string);
-      return;
-    }
-    if (typeof window == "object") {
-      return;
-    }
-    if (typeof print == "function") {
-      print(string);
-      return;
-    }
-    throw "Unable to print message: " + String(string);
-  }
-  dart.fn(printString, dart.void, [core.String]);
-  // Exports:
-  exports.printString = printString;
-});