Parser: Error when let is embedded inside other expression

[lth]

The parens are required around the "let" expression in this function, but should not be:

function stringHash(s: string): uint {
    let h = 0;
    for ( let i=0 ; i < s.length ; i++ )
        h = (h << 4) + (let (c = s.charCodeAt(i)) c*3);
    return h;
}

[lth]

See also #114.