Wish: Variable Not Used Warning

[Robert Fraser]

Walter Bright wrote:
> There is a place for warnings, however. That is in a separate static 
> analysis tool (i.e. lint, coverity, etc.) which can be armed with all 
> kinds of heuristics with which to flag questionable constructs. I don't 
> think they should be part of the compiler, however.

The compiler already has full semantic knowledge of the code, and at 
least some of the warnings seem like "low-hanging fruit" so why not make 
the compiler act as a "mini-lint"?