Support `else if (...)`

[Arthur Buldauskas]

Overview

The lack of else if is awkward, makes it difficult to write some code.

A quick solution might be to encode the node as a literal else block containing a single if.

Sample spec

export function test(x: i32): i32 {
   if (x == 0) {
     return 2;
  } else if (x == 1) {
     return 4;
  } else {
     return -1;
  }
}

That should do it.

• Tests
• Tests pass