8241064: JFR related tests TestMetaspaceAllocationFailure.java and TestEventInstrumentation.java miss requires tag

Reviewed-by: mseledtsov, mgronlun

test/jdk/jdk/jfr/event/runtime/TestMetaspaceAllocationFailure.java

@@ -24,6 +24,7 @@
 /**
  * @test
  * @summary Test jdk.MetaspaceAllocationFailure event
+ * @requires vm.hasJFR
  * @library /test/lib
  * @modules java.base/jdk.internal.misc java.compiler
  * @run main/othervm -Xmx1G -XX:MaxMetaspaceSize=200M

test/jdk/jdk/jfr/javaagent/TestEventInstrumentation.java

@@ -48,6 +48,7 @@ import jdk.test.lib.Asserts;
  * @summary Verify that a subclass of the JFR Event class
  *          can be successfully instrumented.
  * @key jfr
+ * @requires vm.hasJFR
  * @library /test/lib
  * @modules java.base/jdk.internal.org.objectweb.asm
  *          jdk.jartool/sun.tools.jar