RFR: 8075735: Missing include causes minimal build failure

[Stefan Johansson]

Hi,

Please review this small change to fix:
https://bugs.openjdk.java.net/browse/JDK-8075735

Webrev:
http://cr.openjdk.java.net/~sjohanss/8075735/hotspot.00/

Summary:
Minimal1 currently does not build in the hs-gc repo. The cause is a 
missing include in thread.cpp, which is added by the proposed change.

Testing:
Verified that minimal1 builds and run after the change.

Thanks,
Stefan