Revert "HHH-18945 Reverted two changes from HHH-18693 - when meta model class is extending another class always use fully qualified class name"

This reverts commit a81c288.

Author: cigaly

tooling/metamodel-generator/src/main/java/org/hibernate/processor/ClassWriter.java

@@ -173,7 +173,8 @@ else if ( modifiers.contains( Modifier.PROTECTED ) ) {
 
 		final Element superTypeElement = entity.getSuperTypeElement();
 		if ( superTypeElement != null ) {
-			pw.print( " extends " + getGeneratedSuperclassName( superTypeElement, entity.isJakartaDataStyle() ) );
+			pw.print( " extends " +
+					entity.importType(getGeneratedSuperclassName( superTypeElement, entity.isJakartaDataStyle() )) );
 		}
 		if ( entity.isImplementation() ) {
 			pw.print( entity.getElement().getKind() == ElementKind.CLASS ? " extends " : " implements " );

tooling/metamodel-generator/src/test/java/org/hibernate/processor/test/separatecompilationunits/SeparateCompilationUnitsTest.java

@@ -28,7 +28,12 @@ public void testInheritance() throws Exception {
 		String entityMetaModel = getMetaModelSourceAsString( Entity.class );
 		assertTrue(
 				entityMetaModel.contains(
-						"extends org.hibernate.processor.test.separatecompilationunits.superclass.MappedSuperclass"
+						"import org.hibernate.processor.test.separatecompilationunits.superclass.MappedSuperclass_;"
+				)
+		);
+		assertTrue(
+				entityMetaModel.contains(
+						"extends MappedSuperclass_"
 				)
 		);
 	}