[TIR]Fix the crash of the pass RemoveNoOp

[lightzhan-intellif]

This PR tries to fix the crash of the pass RemoveNoOp when the condition of IfThenElseNode can be statically determined. For example:

  @L.prim_func
  def remove_no_op():
    if True:
      L.evaluate(0)
    else:
      L.evaluate(0)

This case will cause Segment fault error because RemoveNoOp don't cover the case the return of Parent::VisitStmt_ is not a IfThenElseNode, which will result in the stmt.as<IfThenElseNode>() being null.

[tvm-bot]

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• cc @Hzfengsy, @junrushao, @quic-sanirudh _{See #10317 for details}

_{Generated by tvm-bot}

[Hzfengsy]

LGTM. Thanks for the fixing