javac: binary operator adds erroneous cast on 1st operand.

For example when multiplying Vector to Matrix:

``` java
class VecMat {
    static class Vec {
        Vec multiply(Mat A) { return this; }
    }
    static class Mat {}
    public static void main(String[] s) {
        Vec a = new Vec();
        Mat A = new Mat();
        System.out.println(a*A);
    }
}
```

`a*A` transforms to `((Mat)a).multiply(A)`
which causes ClassCastException at runtime.
