+ added System.CodePointer - a pointer that is able to hold a procedure address in the current memory model

git-svn-id: http://svn.freepascal.org/svn/fpc/trunk@24839 3ad0048d-3df7-0310-abae-a5850022a9f2
* TMethod.Code changed to CodePointer

git-svn-id: http://svn.freepascal.org/svn/fpc/trunk@24840 3ad0048d-3df7-0310-abae-a5850022a9f2