fix(ivy): ngcc generates setClassMetadata calls for ES5 bundles (#27438)

ngcc would feed ngtsc with the function declaration inside of an IIFE as
that is considered the class symbol's declaration node, according to
TypeScript's `ts.Symbol.valueDeclaration`. ngtsc however only considered
variable decls and actual class decls as potential class declarations,
so given the function declaration node it would fail to generate the
`setClassMetadata` call.

ngtsc no longer makes its own assumptions about what classes look like,
but always asks the reflection host to yield this kind of information.

PR Close #27438

packages/compiler-cli/src/ngcc/src/host/esm5_host.ts

@@ -38,7 +38,9 @@ export class Esm5ReflectionHost extends Esm2015ReflectionHost {
   /**
    * Check whether the given node actually represents a class.
    */
-  isClass(node: ts.Node): boolean { return super.isClass(node) || !!this.getClassSymbol(node); }
+  isClass(node: ts.Node): node is ts.NamedDeclaration {
+    return super.isClass(node) || !!this.getClassSymbol(node);
+  }
 
   /**
    * Find a symbol for a node that we think is a class.