Problem was that in mysql-trunk the ER() macro is now dependent on current_thd
and the innodb monitor thread has no binding to that thd object. This cause 
the crash because of bad derefencing.

Solution was to add a new macro which take the thd as an argument (which the innodb
thread uses for the call).

(Updated according to reviewers comments, i.e. added ER_THD_OR_DEFAULT and
moved test to suite parts.)