FpDebugger (pure): Do not try to compile the linux-units on non-linux systems

git-svn-id: http://svn.freepascal.org/svn/lazarus/trunk@45780 4005530d-fff6-0310-9dd1-cebe43e6787f
FpDebugger (pure): On linux all communication with the debuggee has to be done in the thread that started the debuggee.

git-svn-id: http://svn.freepascal.org/svn/lazarus/trunk@45781 4005530d-fff6-0310-9dd1-cebe43e6787f