TypedArrays should support more than `Double` values

From what I can tell in the `integer_entities.txt` update, the build now can generate int or Integer in some cases instead of Double. This doesn't seem to have been applied to the TypedArray subtypes, resulting in some unique `getAt` and `setAt` calls. Working from PlayN sources as I patch them to use elemental2 instead of JSOs, ByteBuffer.getShort now must look like this:

```
public final short getShort (int baseOffset) {
short bytes = 0;
if (order == ByteOrder.BIG_ENDIAN) {
bytes = (short)(((byte) (double) byteArray.getAt(baseOffset)) << 8);
bytes |= (((byte) (double) byteArray.getAt(baseOffset + 1)) & 0xFF);
} else {
bytes = (short) (((byte) (double) byteArray.getAt(baseOffset + 1)) << 8);
bytes |= (((byte) (double) byteArray.getAt(baseOffset)) & 0xFF);
}
return bytes;
}
```

Since `Int8Array` is a `TypedArray` is a `JsArrayLike`, the getAt call returns `Double`, which cannot be shifted, so first we cast to `double`, which _still_ can't be shifted, so cast to `byte`. Technically we could cast to `int` in the second one, but I wanted to be precise here. We of course have to assume that the browser would never return something outside the range of a byte here.

```
public final ByteBuffer putInt (int baseOffset, int value) {
if (order == ByteOrder.BIG_ENDIAN) {
for (int i = 3; i >= 0; i--) {
byteArray.setAt(baseOffset + i, (double)(byte)(value & 0xFF));
value = value >> 8;
}
} else {
for (int i = 0; i <= 3; i++) {
byteArray.setAt(baseOffset + i, (double)(byte)(value & 0xFF));
value = value >> 8;
}
}
return this;
}
```
Same idea here - the `int value` is being shifted and masked, and can't be used directly as a `double`. Granted, the cast to `byte` isn't technically required here, but it does seem less un-clear to a reader than casting an _int_ to a _double_ so you can put it in a _byte_ array.

I'm not sure exactly how this can be improved, without just listing all of these signatures by hand, but this is pretty terrible Java to have to write. At least in the case of PlayN it is hidden behind emul code, but I had understood that elemental2 was meant to be user facing for the most part.