Oh, and a question – is the generated code actually semantically identical? For most uses practical uses, it is, but I think under racy conditions it could give different results.
Effectively this transformation is the same as doing "Convert LINQ to code" and "Extract method" in R# (although those tend to sometimes be unable to codify even simple LINQ expressions).
It doesn't even look right for the example. This line:
num += num2 + 3;
num += _linqitems[i] + 3;The tool works fine, I've tried it out myself
int num2 = _linqitems[i];