build: allow users to have no //:node_modules (#445)

Author: alexeagle

packages/angular_devkit/build_optimizer/BUILD

@@ -25,8 +25,8 @@ ts_library(
             "**/*_spec.ts",
         ],
     ),
-    # Note, intentionally no node_modules attribute - so it will use the
-    # compile-time deps in the downstream repository's //:node_modules.
-    # This creates the assumption that every consumer does have that target.
     tsconfig = "//:tsconfig.json",
+    # Borrow the compile-time deps of the typescript compiler
+    # Just to avoid an extra npm install action.
+    node_modules = "@build_bazel_rules_typescript_tsc_wrapped_deps//:node_modules",
 )