Simplify ClassHierarchyBuilder.getNode

Change-Id: I2ca5197f6f69cf92641493ec865ccfe0bc716a15
Reviewed-on: https://dart-review.googlesource.com/c/88324
Reviewed-by: Dmitry Stefantsov <[email protected]>

Author: peter-ahe-google

pkg/front_end/lib/src/fasta/kernel/class_hierarchy_builder.dart

@@ -386,16 +386,14 @@ class ClassHierarchyBuilder {
   }
 
   ClassHierarchyNode getNode(KernelTypeBuilder type) {
-    if (type is KernelNamedTypeBuilder) {
-      Declaration declaration = type.declaration;
-      if (declaration is KernelClassBuilder) {
-        ClassHierarchyNode node = nodes[declaration];
-        if (node == null && declaration is KernelClassBuilder) {
-          add(declaration);
-          node = nodes[declaration];
-        }
-        return node;
+    Declaration declaration = getDeclaration(type);
+    if (declaration is KernelClassBuilder) {
+      ClassHierarchyNode node = nodes[declaration];
+      if (node == null) {
+        add(declaration);
+        node = nodes[declaration];
       }
+      return node;
     }
     return null;
   }