Dereferencing Arrays Is Not Possible

[IGI-111]

In Sway, developers can create a mutable reference to a variable using something like the following
snippet:

let mut x = 1;
let y = &mut x;
*y = 1

As expected this updates the value of x. However, a mutable reference is not really usable in case of an
array due to limitations in the parsing. In particular, the parser prohibts the use of parentheses on the
left-hand-side of an assignment. The following snippet does not compile:

let mut a = [1, 2];
let mut p = &mut a;
(*p)[1] = 1;