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/platform-browser/animations/package.json

@@ -1,7 +1,7 @@
 {
   "name": "@angular/platform-browser/animations",
-  "typings": "../animations.d.ts",
+  "typings": "./index.d.ts",
   "main": "../bundles/platform-browser-animations.umd.js",
-  "module": "../@angular/platform-browser/animations.es5.js",
-  "es2015": "../@angular/platform-browser/animations.js"
+  "module": "../esm5/animations/index.js",
+  "es2015": "../esm15/animations/index.js"
 }

packages/platform-browser/animations/public_api.ts

@@ -9,6 +9,6 @@
 /**
  * @module
  * @description
- * Entry point for all public APIs of the animation package.
+ * Entry point for all public APIs of this package.
  */
 export * from './src/animations';

packages/platform-browser/animations/rollup.config.js

@@ -7,6 +7,7 @@
  */
 
 import resolve from 'rollup-plugin-node-resolve';
+import sourcemaps from 'rollup-plugin-sourcemaps';
 
 const globals = {
   '@angular/core': 'ng.core',
@@ -17,12 +18,12 @@ const globals = {
 };
 
 export default {
-  entry: '../../../dist/packages-dist/platform-browser/@angular/platform-browser/animations.es5.js',
+  entry: '../../../dist/packages-dist/platform-browser/esm5/animations/index.js',
   dest: '../../../dist/packages-dist/platform-browser/bundles/platform-browser-animations.umd.js',
   format: 'umd',
   exports: 'named',
   moduleName: 'ng.platformBrowser.animations',
-  plugins: [resolve()],
+  plugins: [resolve(), sourcemaps()],
   external: Object.keys(globals),
   globals: globals
 };

packages/platform-browser/animations/tsconfig-build.json

@@ -1,21 +1,26 @@
 {
-  "extends": "../tsconfig-build",
+  "extends": "../tsconfig-build.json",
 
   "compilerOptions": {
+    "baseUrl": ".",
+    "rootDir": "../",
     "paths": {
-      "rxjs/*": ["../../node_modules/rxjs/*"],
-      "@angular/core": ["../../dist/packages/core"],
-      "@angular/core/testing": ["../../dist/packages/core/testing"],
-      "@angular/animations": ["../../dist/packages/animations"],
-      "@angular/animations/browser": ["../../dist/packages/animations/browser"],
-      "@angular/platform-browser": ["../../dist/packages/platform-browser"]
-    }
+      "rxjs/*": ["../../../node_modules/rxjs/*"],
+      "@angular/core": ["../../../dist/packages/core"],
+      "@angular/core/testing": ["../../../dist/packages/core/testing"],
+      "@angular/animations": ["../../../dist/packages/animations"],
+      "@angular/animations/browser": ["../../../dist/packages/animations/browser"],
+      "@angular/platform-browser": ["../../../dist/packages/platform-browser"]
+    },
+    "outDir": "../../../dist/packages/platform-browser"
   },
+
   "files": [
     "public_api.ts",
     "../../../node_modules/zone.js/dist/zone.js.d.ts",
     "../../system.d.ts"
   ],
+
   "angularCompilerOptions": {
     "annotateForClosureCompiler": true,
     "strictMetadataEmit": true,