inline 2

Is it possible to add support for inline functions?
```
export function test(x:i32, y:i32):i32 {
    x = add( x, 1 );
    y = add( y, 1 );
    return add( x, y );
}

inline function add(x:i32, y:i32):i32 {
    return x + y;
}
```
That should be optimized to
```
export function test(x:i32, y:i32):i32 {
    x = x + 1;
    y = y + 1;
    return x + y;
}
```