Amiga: updated sysutils unit to equal the MorphOS version in features

git-svn-id: http://svn.freepascal.org/svn/fpc/trunk@27055 3ad0048d-3df7-0310-abae-a5850022a9f2
AMIGAOS4 is now defined in the compiler, not in the RTL

git-svn-id: http://svn.freepascal.org/svn/fpc/trunk@27056 3ad0048d-3df7-0310-abae-a5850022a9f2