build: publish tree of files rather than FESMs (#18541)

* Remove now unnecessary portions of build.
* Add a compilePackageES5 method to build ES5 from sources
* Rework all package.json and rollup config files to new format
* Remove "extends" from tsconfig-build.json files and fixup compilation roots

PR Close #18541

packages/language-service/package.json

@@ -3,8 +3,8 @@
   "version": "0.0.0-PLACEHOLDER",
   "description": "Angular - language services",
   "main": "./bundles/language-service.umd.js",
-  "module": "./@angular/language-service.es5.js",
-  "typings": "./language-service.d.ts",
+  "module": "./esm5/index.js",
+  "typings": "./index.d.ts",
   "author": "angular",
   "license": "MIT",
   "repository": {

packages/language-service/rollup.config.js

@@ -7,6 +7,7 @@
  */
 
 import commonjs from 'rollup-plugin-commonjs';
+import sourcemaps from 'rollup-plugin-sourcemaps';
 import * as path from 'path';
 
 var m = /^\@angular\/((\w|\-)+)(\/(\w|\d|\/|\-)+)?$/;
@@ -39,7 +40,8 @@ function resolve(id, from) {
     var esm_suffix = esm_suffixes[packageName] || '';
     var loc = locations[packageName] || location;
     var r = loc !== location && (loc + esm_suffix + packageName + (match[3] || '/index') + '.js') ||
-        loc + packageName + '/@angular/' + packageName + '.es5.js';
+        loc + packageName + '/esm5/' +
+            'index.js';
     // console.log('** ANGULAR MAPPED **: ', r);
     return r;
   }
@@ -69,7 +71,7 @@ module.exports = function(provided) {
 `;
 
 export default {
-  entry: '../../dist/packages-dist/language-service/@angular/language-service.es5.js',
+  entry: '../../dist/packages-dist/language-service/esm5/index.js',
   dest: '../../dist/packages-dist/language-service/bundles/language-service.umd.js',
   format: 'amd',
   moduleName: 'ng.language_service',
@@ -85,5 +87,5 @@ export default {
     'fs': 'fs',
   },
   banner: banner,
-  plugins: [{resolveId: resolve}, commonjs()]
+  plugins: [{resolveId: resolve}, commonjs(), sourcemaps()]
 }

packages/language-service/tsconfig-build.json

@@ -1,14 +1,10 @@
 {
+  "extends": "../tsconfig-build.json",
+
   "compilerOptions": {
-    "baseUrl": ".",
-    "declaration": true,
-    "stripInternal": true,
     "emitDecoratorMetadata": true,
-    "experimentalDecorators": true,
-    "strictNullChecks": true,
-    "module": "es2015",
-    "moduleResolution": "node",
-    "outDir": "../../dist/packages/language-service",
+    "baseUrl": ".",
+    "rootDir": ".",
     "paths": {
       "@angular/core": ["../../dist/packages/core"],
       "@angular/animation": ["../../dist/packages/animation"],
@@ -24,13 +20,9 @@
       "@angular/tsc-wrapped": ["../../dist/packages-dist/tsc-wrapped"],
       "@angular/tsc-wrapped/*": ["../../dist/packages-dist/tsc-wrapped/*"]
     },
-    "rootDir": ".",
-    "sourceMap": true,
-    "inlineSources": true,
-    "target": "es5",
-    "skipLibCheck": true,
-    "lib": ["es2015", "dom"]
+    "outDir": "../../dist/packages/language-service"
   },
+
   "files": [
     "index.ts",
     "../../node_modules/zone.js/dist/zone.js.d.ts",