feat: support multi-dimensional static initialisers

[DavePearce]

Summary

Currently, static initialisers work well for one-dimensional data (both in terms of inputs and outputs). However, they exhibit perhaps unexpected behaviour for multi-dimensional arrays. At this stage, its not completely clear to me what the right behaviour is.

Example 1 --- Multidimensional Input

static table(address:u16, flag:u1) -> (word:u8) {
  0x1, 0x2, 0x3, 0x4
}

pub output out(address:u16) -> (word:u8)

// copy input to output
fn main() {
  out[0] = table[0,0]
  out[1] = table[0,1]
  out[2] = table[1,0]
  out[3] = table[1,1]  
  return
}

This generates the output:

out = 0x01020304

This feels a little odd to me as, normally, arrays accesses bind with the most significant dimension first (e.g. in arr[x][y] is most significant).

Example 2 --- Multidimensional output

Likewise, the following cannot be made to compile for any replacement of ... other than the empty initialiser:

static table(address:u4, flag:u1) -> (left:u8, right:u4) {
  ...
}