perf(compiler): don’t emit summaries for jit by default

This re-adds the flag `enableSummariesForJit` to the compiler options
that already existed in Angular 4.

packages/compiler-cli/integrationtest/tsconfig-xi18n.json

@@ -3,7 +3,8 @@
     // For TypeScript 1.8, we have to lay out generated files
     // in the same source directory with your code.
     "genDir": ".",
-    "debug": true
+    "debug": true,
+    "enableSummariesForJit": true
   },
 
   "compilerOptions": {