Summary:
Backport of JFR(jdk part) to dragonwell based on JFR preview version(JDK11).
Link:
http://cr.openjdk.java.net/~mgronlun/JEP328_FlightRecorder/Preview/webrev/index.html

Test Plan: test/jdk/jfr/

Reviewers: 卓昂, 传胜, 麦庶, yumin.qi, 三红, 芳玺

Reviewed By: 三红, 芳玺, 卓昂, yumin.qi

Differential Revision: https://aone.alibaba-inc.com/code/D818249

Reviewed-by: darcy, weijun

Summary: Update copyright headers to GPL
Reviewed-by: xdono

Summary: Initial checkin of JSDT code
Reviewed-by: sspitsyn, sbohne