Fix NPE in Constructor predicate

This commit fixes a NullPointerException issue in the constructor hint
predicate. Prior to this commit, a hint for a constructor was directly
looked up and dereferenced a type hint without checking if there was one
first.

Author: bclozel

spring-core/src/main/java/org/springframework/aot/hint/ReflectionHintsPredicates.java

@@ -286,7 +286,8 @@ MemberCategory[] getDeclaredMemberCategories() {
 
 		@Override
 		Predicate<RuntimeHints> exactMatch() {
-			return hints -> hints.reflection().getTypeHint(this.executable.getDeclaringClass()).constructors().anyMatch(executableHint -> {
+			return hints -> (hints.reflection().getTypeHint(this.executable.getDeclaringClass()) != null) &&
+					hints.reflection().getTypeHint(this.executable.getDeclaringClass()).constructors().anyMatch(executableHint -> {
 				List<TypeReference> parameters = Arrays.stream(this.executable.getParameterTypes()).map(TypeReference::of).toList();
 				ExecutableHint syntheticHint = ExecutableHint.ofConstructor(parameters)
 						.setModes(this.executableMode).build();

spring-core/src/test/java/org/springframework/aot/hint/ReflectionHintsPredicatesTests.java

@@ -136,6 +136,11 @@ void typeWithAnyMemberCategoryDoesNotMatchOtherCategory() {
 	@Nested
 	class ReflectionOnConstructor {
 
+		@Test
+		void constructorIntrospectionDoesNotMatchMissingHint() {
+			assertPredicateDoesNotMatch(reflection.onConstructor(publicConstructor).introspect());
+		}
+
 		@Test
 		void constructorIntrospectionMatchesConstructorHint() {
 			runtimeHints.reflection().registerType(SampleClass.class, typeHint -> typeHint.withConstructor(Collections.emptyList(), constructorHint -> {