[Integrated] RFR: 6767: Empty filter regex should not be compiled

[Henrik Dafgård]

Changeset: ef58489b
Author:    Henrik Dafgård <hdafgard at openjdk.org>
Date:      2020-04-20 15:15:51 +0000
URL:       https://git.openjdk.java.net/jmc/commit/ef58489b

6767: Empty filter regex should not be compiled

Reviewed-by: hirt

! core/org.openjdk.jmc.common/src/main/java/org/openjdk/jmc/common/item/ItemFilters.java
! core/org.openjdk.jmc.flightrecorder.rules.jdk/src/main/java/org/openjdk/jmc/flightrecorder/rules/jdk/latency/JavaBlockingRule.java
! core/tests/org.openjdk.jmc.flightrecorder.rules.jdk.test/src/test/resources/baseline/JfrRuleBaseline.xml