hg: jdk10/sandbox/jdk: 8184808: (process) isAlive should use pid for validity, not /proc/pid

[chris.hegarty at oracle.com]

Changeset: 03088af6fd97
Author:    rriggs
Date:      2017-07-19 16:24 -0400
URL:       http://hg.openjdk.java.net/jdk10/sandbox/jdk/rev/03088af6fd97

8184808: (process) isAlive should use pid for validity, not /proc/pid
Reviewed-by: stuefe, xiaofeya

! src/java.base/unix/native/libjava/ProcessHandleImpl_unix.c