clone: datatype-type override crashes (CoreIncompatible) when an operator matches on a constructor

[strub]

When a datatype's type is overridden during cloning, an operator whose body
pattern-matches on the datatype's constructors (i.e. compiles to OP_Fix)
triggers an anomaly during the operator-compatibility check.

MRE

theory Thy.
  type ATy = [ CB of int ].
  op getit (x : ATy) = with x = CB n => n.
end Thy.

clone Thy as Thy1.

clone Thy as Thy2 with
  type ATy = Thy1.ATy,
  op getit <= Thy1.getit.

Result:

anomaly: EcLib.EcTheoryReplay.CoreIncompatible

Reproduces on main in both override modes (type ATy = ... and type ATy <- ...).

Cause

Same root cause as #989: when a datatype's type is overridden, the source
datatype's constructors are not re-created in the clone, so references to them
must be redirected to the target datatype's constructors.
EcTheoryReplay.replay_tyd performs this redirect only for OP_Constr
references, not for OP_Fix match bodies.

PR #1045 (fixing #989) extends the redirect to plain constructor references in
both override modes, but does not widen it to OP_Fix.