no longer define a segment field for m68k

git-svn-id: http://svn.freepascal.org/svn/fpc/trunk@26464 3ad0048d-3df7-0310-abae-a5850022a9f2
fix infinite spilling on m68k, patch by Florian, additional IE workaround by me, based on a similar hack in the ARM cg...

git-svn-id: http://svn.freepascal.org/svn/fpc/trunk@26465 3ad0048d-3df7-0310-abae-a5850022a9f2