build(bazel): do not build rxjs from source under Bazel (#28869)

PR Close #28869

tools/defaults.bzl

@@ -165,6 +165,7 @@ def ts_web_test_suite(bootstrap = [], deps = [], **kwargs):
         bootstrap = ["//:web_test_bootstrap_scripts"]
     local_deps = [
         "@ngdeps//node_modules/tslib:tslib.js",
+        "//tools/rxjs:rxjs_umd_modules",
         "//tools/testing:browser",
     ] + deps
 

tools/rxjs/BUILD.bazel

@@ -0,0 +1,9 @@
+package(default_visibility = ["//visibility:public"])
+
+filegroup(
+    name = "rxjs_umd_modules",
+    srcs = [
+        ":rxjs_shims.js",
+        "@ngdeps//node_modules/rxjs:bundles/rxjs.umd.js",
+    ],
+)

tools/rxjs/rxjs_shims.js

@@ -0,0 +1,35 @@
+/**
+ * @license
+ * Copyright Google Inc. All Rights Reserved.
+ *
+ * Use of this source code is governed by an MIT-style license that can be
+ * found in the LICENSE file at https://angular.io/license
+ */
+
+// rxjs/operators
+(function(factory) {
+  if (typeof module === 'object' && typeof module.exports === 'object') {
+    var v = factory(require, exports);
+    if (v !== undefined) module.exports = v;
+  } else if (typeof define === 'function' && define.amd) {
+    define('rxjs/operators', ['exports', 'rxjs'], factory);
+  }
+})(function(exports, rxjs) {
+  'use strict';
+  Object.keys(rxjs.operators).forEach(function(key) { exports[key] = rxjs.operators[key]; });
+  Object.defineProperty(exports, '__esModule', {value: true});
+});
+
+// rxjs/testing
+(function(factory) {
+  if (typeof module === 'object' && typeof module.exports === 'object') {
+    var v = factory(require, exports);
+    if (v !== undefined) module.exports = v;
+  } else if (typeof define === 'function' && define.amd) {
+    define('rxjs/testing', ['exports', 'rxjs'], factory);
+  }
+})(function(exports, rxjs) {
+  'use strict';
+  Object.keys(rxjs.testing).forEach(function(key) { exports[key] = rxjs.testing[key]; });
+  Object.defineProperty(exports, '__esModule', {value: true});
+});