Function replaceRange

replaceRange(
    program: Program,
    start: number,
    end: number,
    instructions: Instruction[],
): Program
Replaces an inclusive range of instructions.
Parameters
- program: Program
  Program to edit.
- start: number
  First index to replace.
- end: number
  Last index to replace, inclusive.
- instructions: Instruction[]
  Instructions inserted in place of the range.
Returns Program
A new program; the input is left untouched.