Avoid infinite recursion for self-referencing generic type

Closes gh-32282
See gh-30079

spring-core/src/test/java/org/springframework/core/ResolvableTypeTests.java

@@ -1321,6 +1321,18 @@ class ResolvableTypeTests {
 		assertThat(type.hasUnresolvableGenerics()).isTrue();
 	}
 
+	@Test
+	void hasUnresolvableGenericsWhenSelfReferring() {
+		ResolvableType type = ResolvableType.forInstance(new Bar());
+		assertThat(type.hasUnresolvableGenerics()).isFalse();
+	}
+
+	@Test
+	void hasUnresolvableGenericsWithEnum() {
+		ResolvableType type = ResolvableType.forType(SimpleEnum.class.getGenericSuperclass());
+		assertThat(type.hasUnresolvableGenerics()).isFalse();
+	}
+
 	@Test
 	void spr11219() throws Exception {
 		ResolvableType type = ResolvableType.forField(BaseProvider.class.getField("stuff"), BaseProvider.class);
@@ -1624,12 +1636,22 @@ class ResolvableTypeTests {
 	}
 
 
-	public interface ListOfListSupplier<T> {
+	interface ListOfListSupplier<T> {
 
 		List<List<T>> get();
-
 	}
 
+
+	class Foo<T extends Foo<T>> {
+	}
+
+	class Bar extends Foo<Bar> {
+	}
+
+
+	enum SimpleEnum { VALUE }
+
+
 	static class EnclosedInParameterizedType<T> {
 
 		static class InnerRaw {