fix(ivy): don't crash on an unknown localref target (#33454)

Previously the template binder would crash when encountering an unknown
localref (# reference) such as `<div #ref="foo">` when no directive has
`exportAs: "foo"`.

With this commit, the compiler instead generates a template diagnostic error
informing the user about the invalid reference.

PR Close #33454

packages/compiler-cli/test/ngtsc/ngtsc_spec.ts

@@ -3137,6 +3137,24 @@ runInEachFileSystem(os => {
       });
     });
 
+    describe('local refs', () => {
+      it('should not generate an error when a local ref is unresolved' +
+             ' (outside of template type-checking)',
+         () => {
+
+           env.write('test.ts', `
+          import {Component} from '@angular/core';
+  
+          @Component({
+            template: '<div #ref="unknownTarget"></div>',
+          })
+          export class TestCmp {}
+        `);
+           const diags = env.driveDiagnostics();
+           expect(diags.length).toBe(0);
+         });
+    });
+
     describe('multiple local refs', () => {
       const getComponentScript = (template: string): string => `
       import {Component, Directive, NgModule} from '@angular/core';

packages/compiler-cli/test/ngtsc/template_typecheck_spec.ts

@@ -714,6 +714,27 @@ export declare class AnimationEvent {
       env.driveMain();
     });
 
+    it('should report an error with an unknown local ref target', () => {
+      env.write('test.ts', `
+        import {Component, NgModule} from '@angular/core';
+
+        @Component({
+          selector: 'test',
+          template: '<div #ref="unknownTarget"></div>',
+        })
+        class TestCmp {}
+
+        @NgModule({
+          declarations: [TestCmp],
+        })
+        class Module {}
+      `);
+      const diags = env.driveDiagnostics();
+      expect(diags.length).toBe(1);
+      expect(diags[0].messageText).toBe(`No directive found with exportAs 'unknownTarget'.`);
+      expect(getSourceCodeForDiagnostic(diags[0])).toBe('unknownTarget');
+    });
+
     it('should report an error with pipe bindings', () => {
       env.write('test.ts', `
     import {CommonModule} from '@angular/common';