0.0 treated as -0.0 in VM, depending on order, causing further differences bw RT and CT

[timotheecour]

-0.0 == 0.0 but that shouldn't mean they're interchangeable; see example below; in particular conflating these breaks further math such as 1/x being inf vs -inf, or breaks things relying on copySign (#16406)

Example

when true:
  proc main =
    let a1 = 0.0
    let a2 = -0.0
    let a3 = 1.0 / a1
    let a4 = 1.0 / a2
    echo (a1, a2, a3, a4)
  static: main()
  main()

Current Output

(0.0, 0.0, inf, inf)
(0.0, -0.0, inf, -inf)

Expected Output

(0.0, -0.0, inf, -inf)
(0.0, -0.0, inf, -inf)

Additional Information

• devel 1.5.1 7256afb
• root cause of P2 in copySign PR Add math.copySign #16406 (comment)