RFR(10)(M): 8179498: attach in linux should be relative to /proc/pid/root and namespace aware

[Chris Plummer]

[re-sending - sent to wrong alias first time]

Hello,
Please review the following:

https://bugs.openjdk.java.net/browse/JDK-8179498
http://cr.openjdk.java.net/~cjplummer/8179498/webrev.00/webrev_jdk/

The CR has the relevant details. Some previous discussions can be found 
here:

http://mail.openjdk.java.net/pipermail/serviceability-dev/2017-April/021237.html 

http://mail.openjdk.java.net/pipermail/serviceability-dev/2017-May/021249.html 

http://mail.openjdk.java.net/pipermail/serviceability-dev/2017-August/021679.html 


Testing with docker has been limited to just making sure jcmd now works 
with the docker setup I was provided. I currently don't see how we can 
run our existing tests in a way that would test the docker support 
without doing some rewriting of the tests.

I also ran all our hotspot tier1, 2, and 3 tests, along with 
jdk/test/tools and jdk/test/sun/tools tests to make sure existing 
functionality is not broken with these changes.

thanks,

Chris