Add COMP-5 binary size test - #285

Boa, that is an old one... so we have some changes in #197 in codegen (referenced here in the Changelog but nothing in the changed files) and all of @rbowler , @ddeclerck and @GitMensch working on it.

The tests here look reasonable.... @lefessan Could you reabase that (here or in another PR) checking if any parts of codegen should be adjusted as well + have a look at the Changelog (strange that only my name was in there)?

Note: I've just verified that the 2-4-8 is definitely correct for acu (no easy micro-focus environment to test against any more) and the 2-4-8 returns the expected values.
Also tested the same on IBM - outputs the same numeric sizes.

Note: For portability reasons LENGTH OF should be used in the test instead of the intrinsic function:

• old acu doesn't have it
• IBM does not allow to DISPLAY a binary integer, which is the result of this function

Side note: IBM also does not allow

       01 WS-SP17 PIC SVPP9(17) COMP-5.
       01 WS-SP18 PIC SVPP9(18) COMP-5.

complaining it includes more than 18 digits.

I have rebased it. It sounds like it's mostly the work of Roger, so maybe I can just squash everything in one of his commits and put the Changelog entry to his name ?

I cleaned the tests (BYTE-LENGTH replaced by LENGTH OF and WS-SP17/18 removed)