feat(compiler-cli): require node 8 as runtime engine (#22669)

This is not expected to be a breaking change for anyone who's on Node LTS (currently v8)
and aligns @angular/compilar-cli with @angular/cli's runtime requirements.

PR Close #22669

packages/compiler-cli/package.json

@@ -18,6 +18,9 @@
     "typescript": ">=2.7.2 <2.8",
     "@angular/compiler": "0.0.0-PLACEHOLDER"
   },
+  "engines" : {
+    "node" : ">=8.0"
+  },
   "repository": {
     "type": "git",
     "url": "https://github.com/angular/angular.git"

packages/compiler-cli/tsconfig-build.json

@@ -4,7 +4,10 @@
   "compilerOptions": {
     "module": "commonjs",
     "stripInternal": false,
-    "target": "es5",
+    "target": "es2015",
+    "lib": [
+      "es2015"
+    ],
     "baseUrl": ".",
     "rootDir": ".",
     "paths": {

packages/compiler-cli/tsconfig.json

@@ -0,0 +1,9 @@
+{
+    "extends": "./tsconfig.json",
+    "compilerOptions": {
+        "target": "es2015",
+        "lib": [
+            "es2015"
+        ]
+    }
+}