feat(ngcc): migrate services that are missing @Injectable() (#33362)

A class that is provided as Angular service is required to have an
`@Injectable()` decorator so that the compiler generates its injectable
definition for the runtime. Applications are automatically migrated
using the "missing-injectable" schematic, however libraries built for
older version of Angular may not yet satisfy this requirement.

This commit ports the "missing-injectable" schematic to a migration that
is ran when ngcc is processing a library. This ensures that any service
that is provided from an NgModule or Directive/Component will have an
`@Injectable()` decorator.

PR Close #33362

packages/compiler-cli/ngcc/src/analysis/migration_host.ts

@@ -6,15 +6,18 @@
  * found in the LICENSE file at https://angular.io/license
  */
 import * as ts from 'typescript';
+
 import {ErrorCode, FatalDiagnosticError} from '../../../src/ngtsc/diagnostics';
+import {AbsoluteFsPath} from '../../../src/ngtsc/file_system';
 import {MetadataReader} from '../../../src/ngtsc/metadata';
 import {PartialEvaluator} from '../../../src/ngtsc/partial_evaluator';
 import {ClassDeclaration, Decorator} from '../../../src/ngtsc/reflection';
 import {DecoratorHandler} from '../../../src/ngtsc/transform';
 import {NgccReflectionHost} from '../host/ngcc_host';
 import {MigrationHost} from '../migrations/migration';
+
 import {AnalyzedClass, AnalyzedFile} from './types';
-import {analyzeDecorators} from './util';
+import {analyzeDecorators, isWithinPackage} from './util';
 
 /**
  * The standard implementation of `MigrationHost`, which is created by the
@@ -24,7 +27,7 @@ export class DefaultMigrationHost implements MigrationHost {
   constructor(
       readonly reflectionHost: NgccReflectionHost, readonly metadata: MetadataReader,
       readonly evaluator: PartialEvaluator, private handlers: DecoratorHandler<any, any>[],
-      private analyzedFiles: AnalyzedFile[]) {}
+      private entryPointPath: AbsoluteFsPath, private analyzedFiles: AnalyzedFile[]) {}
 
   injectSyntheticDecorator(clazz: ClassDeclaration, decorator: Decorator): void {
     const classSymbol = this.reflectionHost.getClassSymbol(clazz) !;
@@ -41,6 +44,25 @@ export class DefaultMigrationHost implements MigrationHost {
       mergeAnalyzedClasses(oldAnalyzedClass, newAnalyzedClass);
     }
   }
+
+  getAllDecorators(clazz: ClassDeclaration): Decorator[]|null {
+    const sourceFile = clazz.getSourceFile();
+    const analyzedFile = this.analyzedFiles.find(file => file.sourceFile === sourceFile);
+    if (analyzedFile === undefined) {
+      return null;
+    }
+
+    const analyzedClass = analyzedFile.analyzedClasses.find(c => c.declaration === clazz);
+    if (analyzedClass === undefined) {
+      return null;
+    }
+
+    return analyzedClass.decorators;
+  }
+
+  isInScope(clazz: ClassDeclaration): boolean {
+    return isWithinPackage(this.entryPointPath, clazz.getSourceFile());
+  }
 }
 
 function getOrCreateAnalyzedFile(