refactor(compiler-cli): ensure `isNamed....()` helpers check name is identity (#38959) (#39272)

Previously the `node.name` property was only checked to ensure it was
defined. But that meant that it was a `ts.BindingName`, which also includes
`ts.BindingPattern`, which we do not support. But these helper methods were
forcefully casting the value to `ts.Identifier.

Now we also check that the `node.name` is actually an `ts.Identifier`.

PR Close #38959

PR Close #39272

packages/compiler-cli/src/ngtsc/reflection/src/util.ts

@@ -11,15 +11,19 @@ import {ClassDeclaration} from './host';
 
 export function isNamedClassDeclaration(node: ts.Node):
     node is ClassDeclaration<ts.ClassDeclaration> {
-  return ts.isClassDeclaration(node) && (node.name !== undefined);
+  return ts.isClassDeclaration(node) && isIdentifier(node.name);
 }
 
 export function isNamedFunctionDeclaration(node: ts.Node):
     node is ClassDeclaration<ts.FunctionDeclaration> {
-  return ts.isFunctionDeclaration(node) && (node.name !== undefined);
+  return ts.isFunctionDeclaration(node) && isIdentifier(node.name);
 }
 
 export function isNamedVariableDeclaration(node: ts.Node):
     node is ClassDeclaration<ts.VariableDeclaration> {
-  return ts.isVariableDeclaration(node) && (node.name !== undefined);
+  return ts.isVariableDeclaration(node) && isIdentifier(node.name);
+}
+
+function isIdentifier(node: ts.Node|undefined): node is ts.Identifier {
+  return node !== undefined && ts.isIdentifier(node);
 }