8216049: stringTable::intern creates redundant String when looking up existing one Reviewed-by: redestad, gziemski, rehn, zgu, jiangli

8204551: Event descriptions are truncated in logs Reviewed-by: coleenp, coleenp

8219011: Implement MacroAssembler::warn method on AArch64 Reviewed-by: adinn

8218941: jdb should support a dbgtrace command that acts the same as the dbgtrace command line option Summary: added dbgtrace command. Reviewed-by: sspitsyn, amenkov, gadams

8215249: Miscellaneous changes imported from jsr166 CVS 2019-02 Reviewed-by: martin, chegar, dholmes

8215363: needless signals in ForkJoinPool Reviewed-by: martin, chegar, dholmes

8215359: InnocuousForkJoinWorkerThread.setContextClassLoader needlessly throws Reviewed-by: martin, chegar, dholmes, reinhapa, alanb

8195057: java/util/concurrent/CountDownLatch/Basic.java failed w/ Xcomp Reviewed-by: martin, chegar, dholmes

8219006: AArch64: Register corruption in slow subtype check Reviewed-by: adinn

8218851: JVM crash in custom classloader stress test, JDK 12 & 13 Summary: Handle NULL and unloaded constraint class in loader constraint table, also cope with unloaded but not cleaned out klass in loader constraint entries. Reviewed-by: hseigel, huntch, stuefe