[11u]: RFR CSR backport: JDK-8220362: Add "POSIX_SPAWN" as valid value to jdk.lang.Process.launchMechanism on Linux

[Langer, Christoph]

Hi,

please review the CSR backport https://bugs.openjdk.java.net/browse/JDK-8220362.

It is the backport of https://bugs.openjdk.java.net/browse/JDK-8214511 to JDK11.

We want to backport 
JDK-8212828<https://bugs.openjdk.java.net/browse/JDK-8212828> to jdk11u and 
hence backporting the CSR is a prerequisite. The CSR is, however, more or less 
identical for 11u.

Thank you and Best regards
Christoph