define PDL_BAD_CODE C macro during compilation of PP BadCode

PP BadCode is often almost identical to PP Code, and it makes sense to
reuse the same code whenever possible.  This macro aids in that.
convert aaa_load.t to Test::More
consolidate test helper function of form `ok( $no, $result )`

All `ok()` helper functions of the above form are consolidated to
`num_ok( $no, $result )`. This function is in t/lib/TestHelper.pm and is
exported into all files that use it.

Future cleanup will turn `num_ok()` calls into `Test::More::ok($result)`.
done_testing not needed
consolidate more ok() functions from various test files
Merge branch 'test-cleanup' of github.com:zmughal/pdl into test-cleanup