As with the other update scripts this takes the output of
-passes=print<gisel-value-tracking> and inserts the results into an
existing mir file. This means that the input is a lot like
update_analysis_test_checks.py, and the output needs to insert into a
mir file similarly to update_mir_test_checks.py. The code used to do the
inserting has been moved to common, to allow it to be reused. Otherwise
it tries to reuse the existing infrastructure, and
update_givaluetracking_test_checks is kept relatively short.