[SPARK-45295][CORE][SQL] Remove Utils.isMemberClass workaround for JDK 8

common/utils/src/main/scala/org/apache/spark/util/SparkClassUtils.scala

@@ -50,34 +50,6 @@ private[spark] trait SparkClassUtils {
   def classIsLoadable(clazz: String): Boolean = {
     Try { classForName(clazz, initialize = false) }.isSuccess
   }
-
-  /**
-   * Returns true if and only if the underlying class is a member class.
-   *
-   * Note: jdk8u throws a "Malformed class name" error if a given class is a deeply-nested
-   * inner class (See SPARK-34607 for details). This issue has already been fixed in jdk9+, so
-   * we can remove this helper method safely if we drop the support of jdk8u.
-   */
-  def isMemberClass(cls: Class[_]): Boolean = {
-    try {
-      cls.isMemberClass
-    } catch {
-      case _: InternalError =>
-        // We emulate jdk8u `Class.isMemberClass` below:
-        //   public boolean isMemberClass() {
-        //     return getSimpleBinaryName() != null && !isLocalOrAnonymousClass();
-        //   }
-        // `getSimpleBinaryName()` returns null if a given class is a top-level class,
-        // so we replace it with `cls.getEnclosingClass != null`. The second condition checks
-        // if a given class is not a local or an anonymous class, so we replace it with
-        // `cls.getEnclosingMethod == null` because `cls.getEnclosingMethod()` return a value
-        // only in either case (JVM Spec 4.8.6).
-        //
-        // Note: The newer jdk evaluates `!isLocalOrAnonymousClass()` first,
-        // we reorder the conditions to follow it.
-        cls.getEnclosingMethod == null && cls.getEnclosingClass != null
-    }
-  }
 }
 
 private[spark] object SparkClassUtils extends SparkClassUtils

sql/api/src/main/scala/org/apache/spark/sql/catalyst/encoders/OuterScopes.scala

@@ -70,7 +70,7 @@ object OuterScopes {
    * useful for inner class defined in REPL.
    */
   def getOuterScope(innerCls: Class[_]): () => AnyRef = {
-    if (!SparkClassUtils.isMemberClass(innerCls)) {
+    if (!innerCls.isMemberClass) {
       return null
     }
     val outerClass = innerCls.getDeclaringClass

sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/expressions/objects/objects.scala

@@ -557,7 +557,7 @@ case class NewInstance(
     // Note that static inner classes (e.g., inner classes within Scala objects) don't need
     // outer pointer registration.
     val needOuterPointer =
-      outerPointer.isEmpty && Utils.isMemberClass(cls) && !Modifier.isStatic(cls.getModifiers)
+      outerPointer.isEmpty && cls.isMemberClass && !Modifier.isStatic(cls.getModifiers)
     childrenResolved && !needOuterPointer
   }