refactor(ivy): ngcc - split work into distinct analyze/compile/execute phases (#32052)

This refactoring more clearly separates the different phases of the work
performed by `ngcc`, setting the ground for being able to run each phase
independently in the future and improve performance via parallelization.

Inspired by/Based on @alxhub's prototype: alxhub/angular@cb631bdb1

PR Close #32052

packages/compiler-cli/ngcc/src/execution/api.ts

@@ -0,0 +1,74 @@
+/**
+ * @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 {EntryPoint, EntryPointJsonProperty} from '../packages/entry_point';
+
+/** The type of the function that analyzes entry-points and creates the list of tasks. */
+export type AnalyzeFn = () => {
+  processingMetadataPerEntryPoint: Map<string, EntryPointProcessingMetadata>;
+  tasks: Task[];
+};
+
+/**
+ * The type of the function that creates the `compile()` function, which in turn can be used to
+ * process tasks.
+ */
+export type CreateCompileFn =
+    (onTaskCompleted: (task: Task, outcome: TaskProcessingOutcome) => void) => (task: Task) => void;
+
+/**
+ * The type of the function that orchestrates and executes the required work (i.e. analyzes the
+ * entry-points, processes the resulting tasks, does book-keeping and validates the final outcome).
+ */
+export type ExecuteFn = (analyzeFn: AnalyzeFn, createCompileFn: CreateCompileFn) => void;
+
+/** Represents metadata related to the processing of an entry-point. */
+export interface EntryPointProcessingMetadata {
+  /**
+   * A mapping from a format property (i.e. an `EntryPointJsonProperty`) to the list of format
+   * properties that point to the same format-path and as a result need to be marked as processed,
+   * once the former is processed.
+   */
+  propertyToPropertiesToMarkAsProcessed: Map<EntryPointJsonProperty, EntryPointJsonProperty[]>;
+
+  /**
+   * Whether the typings for the entry-point have been successfully processed (or were already
+   * processed).
+   */
+  hasProcessedTypings: boolean;
+
+  /**
+   * Whether at least one format has been successfully processed (or was already processed) for the
+   * entry-point.
+   */
+  hasAnyProcessedFormat: boolean;
+}
+
+/** Represents a unit of work: processing a specific format property of an entry-point. */
+export interface Task {
+  /** The `EntryPoint` which needs to be processed as part of the task. */
+  entryPoint: EntryPoint;
+
+  /**
+   * The `package.json` format property to process (i.e. the property which points to the file that
+   * is the program entry-point).
+   */
+  formatProperty: EntryPointJsonProperty;
+
+  /** Whether to also process typings for this entry-point as part of the task. */
+  processDts: boolean;
+}
+
+/** Represents the outcome of processing a `Task`. */
+export const enum TaskProcessingOutcome {
+  /** The target format property was already processed - didn't have to do anything. */
+  AlreadyProcessed,
+
+  /** Successfully processed the target format property. */
+  Processed,
+}