demo_compiler test the presence of a compiler

## Syntax

    status = demo_compiler()

## Description

The function demo_compiler asks the computer if it owns a compiler C or not. It returns a boolean indicating whether the compiler exists or not.

## Examples

    select num,
     case 0
      return;
     case 2 then
      st = demo_compiler(); //The compiler will be used
      if (st==%t) then
        mode(0);
        wheel_build_and_load()
      end
     case 1 then // A precomputed value
      x=read(path+'/x.wrt',8,301);
      wheelg=wheelgs;
      show(x);
    end

## See also

- findmsvccompiler