Support as cast expressions in super class types

Summary:
Changelog [flow-api-translator]: Added support for `class A extends (Foo as Bar)` in the flow-api-translator

D58577282 added support for the legacy `TypeCastExpression`s, but did not add support for `AsExpression`s. Add support here.

Reviewed By: SamChou19815

Differential Revision: D59928177

fbshipit-source-id: 4a1d745428fc016da9dd7004aa8e26d223d09deb

tools/hermes-parser/js/flow-api-translator/__tests__/flowToFlowDef-test.js

@@ -521,6 +521,12 @@ describe('flowToFlowDef', () => {
         `declare export class Foo<T> extends X {}`,
       );
     });
+    it('extends as cast expression', async () => {
+      await expectTranslate(
+        `export class Foo<T> extends (Bar as X) {}`,
+        `declare export class Foo<T> extends X {}`,
+      );
+    });
     it('extends type cast typeof expression', async () => {
       await expectTranslate(
         `export class Foo<T> extends (Bar: typeof X) {}`,

tools/hermes-parser/js/flow-api-translator/src/flowToFlowDef.js

@@ -1047,8 +1047,12 @@ function convertSuperClass(
         context,
       );
     }
-    case 'TypeCastExpression': {
-      const typeAnnotation = superClass.typeAnnotation.typeAnnotation;
+    case 'TypeCastExpression':
+    case 'AsExpression': {
+      const typeAnnotation =
+        superClass.type === 'TypeCastExpression'
+          ? superClass.typeAnnotation.typeAnnotation
+          : superClass.typeAnnotation;
 
       if (typeAnnotation.type === 'GenericTypeAnnotation') {
         return convertSuperClassHelper(