Introduce test for perthis with @Aspect and shared pointcut

This commit modifies PerThisAspect (which is used indirectly in
AspectJAutoProxyCreatorTests.perThisAspect()) so that it uses a shared
@Pointcut for both the @Aspect and @Around declarations, in order to
refute claims made in gh-29998 that the documentation in the reference
manual is incorrect.

spring-context/src/test/java/test/aspect/CommonPointcuts.java

@@ -0,0 +1,30 @@
+/*
+ * Copyright 2002-2023 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package test.aspect;
+
+import org.aspectj.lang.annotation.Pointcut;
+
+/**
+ * @author Sam Brannen
+ * @since 6.0.6
+ */
+public class CommonPointcuts {
+
+	@Pointcut("execution(* getAge())")
+	public void getAgeExecution() {}
+
+}

spring-context/src/test/java/test/aspect/PerThisAspect.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2005 the original author or authors.
+ * Copyright 2002-2023 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -20,7 +20,7 @@ import org.aspectj.lang.ProceedingJoinPoint;
 import org.aspectj.lang.annotation.Around;
 import org.aspectj.lang.annotation.Aspect;
 
-@Aspect("perthis(execution(* getAge()))")
+@Aspect("perthis(test.aspect.CommonPointcuts.getAgeExecution())")
 public class PerThisAspect {
 
 	private int invocations = 0;
@@ -29,9 +29,9 @@ public class PerThisAspect {
 		return this.invocations;
 	}
 
-	@Around("execution(* getAge())")
-	public int changeAge(ProceedingJoinPoint pjp) throws Throwable {
-		return invocations++;
+	@Around("test.aspect.CommonPointcuts.getAgeExecution()")
+	public int changeAge(ProceedingJoinPoint pjp) {
+		return this.invocations++;
 	}
 
 }