on that machine, "perl" calls /usr/local/bin/perl (so this is what
runs unittest's unit.pl), while some test scripts (ma_test_recovery.pl
etc) use /usr/bin/perl which seems to either conflict with /usr/local/bin/perl
or have problems of its own (Perl errors when loading modules).
Instead we use perl from the PATH. /usr/bin/env seems to be available
on lots of Unix machines.


dbug/tests-t.pl:
  look for perl in PATH
storage/maria/unittest/ma_test_all-t:
  Look for perl in PATH
storage/maria/unittest/ma_test_recovery.pl:
  Look for perl in PATH. Close MY_LOG to flush buffers to that diff sees
  the whole file