Do not require full type reflection when listing methods/fields

Prior to this commit, the `RuntimeHintsAgent` and its testing
infrastructure would assume that calling `MyClass.class.getMethods()`
requires a reflection hint on the class for introspecting public/private
methods.

GraalVM does not require this, in fact this call only returns methods
that have reflection hints in the native image.

This commit refines the agent behavior for `Class.getMethods()`,
`Class.getDeclaredMethods()`, `Class.getFields()` and
`Class.getDeclaredFields()`. With this change, registering at least one
method/field for reflection is enough to match.

During the execution of Java tests, all methods and fields will be
provided, regardless of hints being registered or not. This could cause
false negatives where we're missing reflection hints on methods or
fields.
This risk is mitigated thanks to additional instrumentation on
`Method.getAnnotations()`, `Method.getParameterTypes()` and
`Method.invoke()`. If a method is found reflectively, chances are it
will be used for further reflection.

Closes gh-29091

integration-tests/src/test/java/org/springframework/aot/RuntimeHintsAgentTests.java

@@ -164,6 +164,22 @@ public class RuntimeHintsAgentTests {
 						throw new RuntimeException(e);
 					}
 				}, MethodReference.of(Method.class, "invoke")),
+				Arguments.of((Runnable) () -> {
+					try {
+						toStringMethod.getAnnotations();
+					}
+					catch (Exception e) {
+						throw new RuntimeException(e);
+					}
+				}, MethodReference.of(Method.class, "getAnnotations")),
+				Arguments.of((Runnable) () -> {
+					try {
+						toStringMethod.getParameterTypes();
+					}
+					catch (Exception e) {
+						throw new RuntimeException(e);
+					}
+				}, MethodReference.of(Method.class, "getParameterTypes")),
 				Arguments.of((Runnable) () -> {
 					try {
 						privateGreetMethod.invoke(new PrivateClass());