Optimising Shadow Variables

[DavePearce]

Currently, the use of shadow variables is suboptimal. Consider this example:

function f(int x) -> (int r):
    return x + 1

which generates the following JavaScript:

function f_I(/*int*/ x)// -> (/*int*/ r)
{
    // create shadow variables
    var $x = x;
    // function or method body
    var r = x + 1;
    // restore shadow variables
    x = $x;
    return r;
}

Here, we don't really need the $x shadow at all.