+ linux syscalls for arm thumb

git-svn-id: http://svn.freepascal.org/svn/fpc/trunk@23987 3ad0048d-3df7-0310-abae-a5850022a9f2
* fixes several issues with arm thumb stack frame

git-svn-id: http://svn.freepascal.org/svn/fpc/trunk@23988 3ad0048d-3df7-0310-abae-a5850022a9f2