[ES6] Several lexical binding causes SyntaxError if there is duplicate lexical/variable decl under targetting block

[Yusuke Suzuki]

http://ecma-international.org/ecma-262/6.0/#sec-for-statement-static-semantics-early-errors

for (let v = 42;;) {
    var v = 44;
}

should throw SyntaxError

http://ecma-international.org/ecma-262/6.0/#sec-try-statement-static-semantics-early-errors

try {
} catch (error) {
     let error = 42;
}

should throw SyntaxError


try {
} catch (error) {
     var error = 42;
}

should throw SyntaxError