CTEST: Fix MUMPS coverage parsing and test

Fix the MUMPS coverage parser:
 Account for tabs after entry points
 Stop double incrementing lines that have explicit calls to the 0 line
 If a line has been previously marked as non executable, but then contains a
  count, increment it an extra one to push it back into the executable code set.

Add a custom routine and corresponding coverage files.  This file is smaller
and has cmcov/mcov files that have data for only that routine.
Merge topic 'fix_mumps_coverage' into next

67fbc5d5 CTEST: Fix MUMPS coverage parsing and test