[colm] UNKNOWN INSTRUCTION: 0x00 since ecca4b68

[Peter Reijnders]

hello

For the 10.13.0.4 version I created a simple testcase.
This example is now also in the master branch ('doc/code/assign.lm').

However, with the current version, it stopped working.

```
../../src/colm assign.lm && echo -e 'b=3;a=1;\n c=2;' |./assign
fatal:  -- something is wrong
```

'git bisect' revealed that 'aecca4b68436782235c3e1de7b6bab7a977590b2
/implemented a const-string define option -Ename=val' introduced this.
There are many changes in that commit. And it look al complex to me. I
don't know where to start looking for a solution.
Does anybody have an idea?

Peter Reijnders