RFR: 8181313: SA: Remove libthread_db dependency on Linux

[Yasumasa Suenaga]

Hi all,

Please review this change:

  JBS: https://bugs.openjdk.java.net/browse/JDK-8181313
  webrev: http://cr.openjdk.java.net/~ysuenaga/JDK-8181313/webrev.00/

It has passed all tests on submit repo, and serviceability/sa tests on
Linux x64.


Thanks,

Yasumas