New error: Literal values in right-hand side of instanceof

[jugglinmike]

According to ES5 11.8.6:

11.8.6 The instanceof operator

The production RelationalExpression: RelationalExpression instanceof ShiftExpression is evaluated as follows:

1. Let lref be the result of evaluating RelationalExpression.
2. Let lval be GetValue(lref).
3. Let rref be the result of evaluating ShiftExpression.
4. Let rval be GetValue(rref).
5. If Type(rval) is not Object, throw a TypeError exception.
6. If rval does not have a [[HasInstance]] internal method, throw a TypeError
   exception.
7. Return the result of calling the [[HasInstance]] internal method of rval
   with argument lval.

We can't completely enforce this statically, but there are some forms which we can reject
outright. The following instanceof applications should trigger an error:

var x;
x instanceof 0;
x instanceof '';
x instanceof null;
x instanceof undefined;
x instanceof {};
x instanceof [];
x instanceof /./;

And it probably wouldn't hurt to warn on the following cases, too:

x instanceof function() {};
x instanceof function MyUnusableFunction() {};