+ far pointer support in tpointerconstnode

git-svn-id: http://svn.freepascal.org/svn/fpc/trunk@24566 3ad0048d-3df7-0310-abae-a5850022a9f2
+ far pointer fixes in the internal compiler handling of ptr(const,const)

git-svn-id: http://svn.freepascal.org/svn/fpc/trunk@24567 3ad0048d-3df7-0310-abae-a5850022a9f2