The distribution with lazarus is simple an old snapshot. And will (time permitting) be update occasionally.
It is only included because it is used by the IDE itself (editor macros).
IIRC there is one diff in the arm related part. Also some IFDEF are removed.
There are a few changes in the testcase. And recently there was a commit to suppress some of fpc warnings (mainly by adding {%W}), but that may need to be reverted in order to allow updates from upstream.