[15u notice] last 15u-dev merge for 15.0.5

[Yuri Nesterenko]

Hi,

jdk15u-dev is now closed. It will reopen for 15.0.6 release
soon -- almost as planned -- with jdk-15.0.6+0 tag set there.
Last update of master jdk15u repo from jdk15u-dev is finished.
Further changes to 15.0.5, if any, would go directly to
jdk15u and normally should be requested with jdk15u-critical-request.

Thank you!
--yan