refactor(compiler): remove old ngtools api and add listLazyRoutes to new api (#19836)

Usages of `NgTools_InternalApi_NG_2` from `@angular/compiler-cli` will now
throw an error.

Adds `listLazyRoutes` to `@angular/compiler-cli/ngtools2.ts` for getting
the lazy routes of a `ng.Program`.
PR Close #19836

packages/compiler/src/aot/lazy_routes.ts

@@ -0,0 +1,62 @@
+/**
+ * @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
+ */
+
+import {CompileNgModuleMetadata, tokenReference} from '../compile_metadata';
+import {Route} from '../core';
+import {CompileMetadataResolver} from '../metadata_resolver';
+
+import {AotCompilerHost} from './compiler_host';
+import {StaticReflector} from './static_reflector';
+import {StaticSymbol} from './static_symbol';
+
+export interface LazyRoute {
+  module: StaticSymbol;
+  route: string;
+  referencedModule: StaticSymbol;
+}
+
+export function listLazyRoutes(
+    moduleMeta: CompileNgModuleMetadata, reflector: StaticReflector): LazyRoute[] {
+  const allLazyRoutes: LazyRoute[] = [];
+  for (const {provider, module} of moduleMeta.transitiveModule.providers) {
+    if (tokenReference(provider.token) === reflector.ROUTES) {
+      const loadChildren = _collectLoadChildren(provider.useValue);
+      for (const route of loadChildren) {
+        allLazyRoutes.push(parseLazyRoute(route, reflector, module.reference));
+      }
+    }
+  }
+  return allLazyRoutes;
+}
+
+function _collectLoadChildren(routes: string | Route | Route[], target: string[] = []): string[] {
+  if (typeof routes === 'string') {
+    target.push(routes);
+  } else if (Array.isArray(routes)) {
+    for (const route of routes) {
+      _collectLoadChildren(route, target);
+    }
+  } else if (routes.loadChildren) {
+    _collectLoadChildren(routes.loadChildren, target);
+  } else if (routes.children) {
+    _collectLoadChildren(routes.children, target);
+  }
+  return target;
+}
+
+export function parseLazyRoute(
+    route: string, reflector: StaticReflector, module?: StaticSymbol): LazyRoute {
+  const [routePath, routeName] = route.split('#');
+  const referencedModule = reflector.resolveExternalReference(
+      {
+        moduleName: routePath,
+        name: routeName,
+      },
+      module ? module.filePath : undefined);
+  return {route: route, module: module || referencedModule, referencedModule};
+}