-O2 causes colon Hash syntax to become a Pair(Hash, key) inside classes

[catb0t]

class X {
  has Hash colon_inner = Hash(
    :prop => :(:k => :v)
  )

  has Hash colon_outer = :(
    :prop => Hash(:k => :v)
  )

  has Hash colon_both = :(
    :prop => :(:k, :v)
  )

  has Hash colon_none = Hash(
    :prop => Hash(:k, :v)
  )

}

func g {
  var Hash y = :(:k, :())
  say "y:\t#{y}"
}

var x = X()
say "inner:  #{x.colon_inner}"
say "outer:  #{x.colon_outer}"
say "both:   #{x.colon_both}"
say "none:   #{x.colon_none}"

var Hash h = :(:k => :())

say "h: \t#{h}"

g()

say x.colon_outer\{:prop}

With -O2

inner:  Hash("prop" => Pair(Sidef::Types::Hash::Hash, "k"))
outer:  Pair(Sidef::Types::Hash::Hash, "prop")
both:   Pair(Sidef::Types::Hash::Hash, "prop")
none:   Hash("prop" => Hash("k" => "v"))
h: 	Hash("k" => Hash())
y:	Hash("k" => Hash())
Not a HASH reference at (eval 5) line 5.

with -O1 or -O0

inner:  Hash("prop" => Hash("k" => "v"))
outer:  Hash("prop" => Hash("k" => "v"))
both:   Hash("prop" => Hash("k" => "v"))
none:   Hash("prop" => Hash("k" => "v"))
h: 	Hash("k" => Hash())
y:	Hash("k" => Hash())
Hash("k" => "v")

This is another bug I was seeing when I was reporting #79, but I can't reproduce it on -O0 anymore. Hopefully, I'm misremembering and it's not actually possible to see with -O0.

I don't know why this happens anyway? Does Hash.: get MRO'd in the wrong order (Object before Hash) with the Optimizer?