fix(language-service): support TypeScript 2.1 (#13655)

@angular/language-service now supports using TypeScript 2.1 as the
the TypeScript host. TypeScript 2.1 is now also partially supported
in `ngc` but is not recommended as Tsickle does not yet support 2.1.

modules/@angular/compiler-cli/integrationtest/third_party_src/tsconfig-build.json

@@ -15,6 +15,8 @@
     "declaration": true,
     "lib": ["es6", "dom"],
     "baseUrl": ".",
-    "outDir": "../node_modules/third_party"
-  }
+    "outDir": "../node_modules/third_party",
+     // Prevent scanning up the directory tree for types
+    "typeRoots": ["node_modules/@types"]
+ }
 }

modules/@angular/compiler-cli/integrationtest/tsconfig-build.json

@@ -14,7 +14,9 @@
     "rootDir": "",
     "declaration": true,
     "lib": ["es6", "dom"],
-    "baseUrl": "."
+    "baseUrl": ".",
+    // Prevent scanning up the directory tree for types
+    "typeRoots": ["node_modules/@types"]
   },
 
   "files": [