run-program issues with OpenJDK 11

[Eric Timmons]

I just tested this on a fresh Debian Buster VM (to rule out anything
weird from my environment) with openjdk-11-jdk-headless and ABCL 1.7.1
and ended up with the same results:

+ The prebuilt jar is unable to use sys:run-program at all.

+ When built from source, sys:run-program works, but sys:process-pid
  does not.

lisp-implementation-version:

"1.7.1"
"OpenJDK_64-Bit_Server_VM-Debian-11.0.7+10-post-Debian-3deb10u1"
"amd64-Linux-4.19.0.9-amd64"

Mark: I just realized that your use of swank-backend:getpid doesn't
match what I was trying to do. Swank's getpid gets the PID of the
current process, but I was trying to get the PID of a process started
with (sys:run-program ... :wait nil) using sys:process-pid.

-Eric