- adjust commented-out evaluation to avoid warnings.
With code like this
```
#if 0
nxin #eval{ round($nxin / 5) };
#endif
```
The handling of the "#if 0 / #endif" clause uses the plain ISstream
parser to tokenize. This means that the "round(" is parsed as a word
with a mismatched closing ')', whereas the "#eval" parser will slurp
everything in until the closing brace and send it off as a string
to the expression parser.