feat(ivy): first steps towards JIT compilation (#23833)

This commit adds a mechanism by which the @angular/core annotations
for @Component, @Injectable, and @NgModule become decorators which,
when executed at runtime, trigger just-in-time compilation of their
associated types. The activation of these decorators is configured
by the ivy_switch mechanism, ensuring that the Ivy JIT engine does
not get included in Angular bundles unless specifically requested.

PR Close #23833

packages/core/src/render3/jit/environment.ts

@@ -0,0 +1,39 @@
+/**
+ * @license
+ * Copyright Google Inc. All Rights Reserved.
+ *
+ * Use of this source code is governed by an MIT-style license that can be
+ * found in the LICENSE file at https://angular.io/license
+ */
+
+import {defineInjectable} from '../../di/defs';
+import {inject} from '../../di/injector';
+import {defineNgModule} from '../../metadata/ng_module';
+import * as r3 from '../index';
+
+
+/**
+ * A mapping of the @angular/core API surface used in generated expressions to the actual symbols.
+ *
+ * This should be kept up to date with the public exports of @angular/core.
+ */
+export const angularCoreEnv = {
+  'ɵdefineComponent': r3.defineComponent,
+  'defineInjectable': defineInjectable,
+  'ɵdefineNgModule': defineNgModule,
+  'ɵdirectiveInject': r3.directiveInject,
+  'inject': inject,
+  'ɵC': r3.C,
+  'ɵE': r3.E,
+  'ɵe': r3.e,
+  'ɵi1': r3.i1,
+  'ɵi2': r3.i2,
+  'ɵi3': r3.i3,
+  'ɵi4': r3.i4,
+  'ɵi5': r3.i5,
+  'ɵi6': r3.i6,
+  'ɵi7': r3.i7,
+  'ɵi8': r3.i8,
+  'ɵT': r3.T,
+  'ɵt': r3.t,
+};