+ noreturn directive

git-svn-id: http://svn.freepascal.org/svn/fpc/trunk@26003 3ad0048d-3df7-0310-abae-a5850022a9f2
* make use of the noreturn directive for internalerror
* clean up of the internalerror procedure variable in the constexp unit

git-svn-id: http://svn.freepascal.org/svn/fpc/trunk@26004 3ad0048d-3df7-0310-abae-a5850022a9f2