+ introduce tvariantrecbranch to be able to store
  all needed information for iso compatible variant records
* new for variant records as required by iso pascal
+ tests

git-svn-id: http://svn.freepascal.org/svn/fpc/trunk@24241 3ad0048d-3df7-0310-abae-a5850022a9f2
* better error reporting

git-svn-id: http://svn.freepascal.org/svn/fpc/trunk@24242 3ad0048d-3df7-0310-abae-a5850022a9f2