8206093: compiler/graalunit/HotspotTest.java fails in CheckGraalIntrinsics

Ignore encodeBlock intrinsic.

Reviewed-by: kvn

src/jdk.internal.vm.compiler/share/classes/org.graalvm.compiler.hotspot.test/src/org/graalvm/compiler/hotspot/test/CheckGraalIntrinsics.java

@@ -371,6 +371,7 @@ public class CheckGraalIntrinsics extends GraalTest {
         if (isJDK11OrHigher()) {
             // Relevant for Java flight recorder
             add(toBeInvestigated,
+                            "java/util/Base64$Encoder.encodeBlock([BII[BIZ)V",
                             "jdk/jfr/internal/JVM.getEventWriter()Ljava/lang/Object;");
         }