fix replaceChild parameter order

[ahti]

replaceChild expects the new child first, old child second (see MDN).

To observe this issue in action, take the sample code from #523 and add back the VStack wrapping the body for state a, then run and click the button. In Safari, this throws the following:

[Error] NotFoundError: The object can not be found here.
	replaceChild (index.mjs:280)
	swjs_call_function_with_this_no_catch (index.mjs:280)
	wasm-stub
	<?>.wasm-function[$s13JavaScriptKit27invokeNonThrowingJSFunction_9arguments4thisSo10RawJSValueaAA0G0C_SayAA013ConvertibleToK0_pGAA8JSObjectCSgtFAFSayAFGXEfU_AFSRyAFGXEfU_]
	<?>.wasm-function[$s13JavaScriptKit27invokeNonThrowingJSFunction_9arguments4thisSo10RawJSValueaAA0G0C_SayAA013ConvertibleToK0_pGAA8JSObjectCSgtFAFSayAFGXEfU_AFSRyAFGXEfU_TA]
	<?>.wasm-function[$sSRySo10RawJSValueaGABs5Error_pIgydzo_AcBsAD_pIegyrzo_TR]
	<?>.wasm-function[$sSRySo10RawJSValueaGABs5Error_pIgydzo_AcBsAD_pIegyrzo_TRTA]
	<?>.wasm-function[$sSa23withUnsafeBufferPointeryqd__qd__SRyxGKXEKlF]
	<?>.wasm-function[$s13JavaScriptKit27invokeNonThrowingJSFunction_9arguments4thisSo10RawJSValueaAA0G0C_SayAA013ConvertibleToK0_pGAA8JSObjectCSgtFAFSayAFGXEfU_]
	<?>.wasm-function[$s13JavaScriptKit27invokeNonThrowingJSFunction_9arguments4thisSo10RawJSValueaAA0G0C_SayAA013ConvertibleToK0_pGAA8JSObjectCSgtFAFSayAFGXEfU_TA]
	<?>.wasm-function[$sSa13JavaScriptKitAA20ConvertibleToJSValue_pRszlE15withRawJSValuesyqd__qd__SaySo0hF0aGXElF01_ghI0L_yqd0__SayAaB_pG_SiAFzqd0__AFXEtAaB_pRszr___lF]
	<?>.wasm-function[$sSa13JavaScriptKitAA20ConvertibleToJSValue_pRszlE15withRawJSValuesyqd__qd__SaySo0hF0aGXElF01_ghI0L_yqd0__SayAaB_pG_SiAFzqd0__AFXEtAaB_pRszr___lFqd0__AEXEfU_]
	<?>.wasm-function[$sSa13JavaScriptKitAA20ConvertibleToJSValue_pRszlE15withRawJSValuesyqd__qd__SaySo0hF0aGXElF01_ghI0L_yqd0__SayAaB_pG_SiAFzqd0__AFXEtAaB_pRszr___lFqd0__AEXEfU_TA]
	<?>.wasm-function[$s13JavaScriptKit7JSValueO07withRawD0yxxSo0fD0aXElF]
	<?>.wasm-function[$sSa13JavaScriptKitAA20ConvertibleToJSValue_pRszlE15withRawJSValuesyqd__qd__SaySo0hF0aGXElF01_ghI0L_yqd0__SayAaB_pG_SiAFzqd0__AFXEtAaB_pRszr___lF]
	<?>.wasm-function[$sSa13JavaScriptKitAA20ConvertibleToJSValue_pRszlE15withRawJSValuesyqd__qd__SaySo0hF0aGXElF01_ghI0L_yqd0__SayAaB_pG_SiAFzqd0__AFXEtAaB_pRszr___lFqd0__AEXEfU_]
	<?>.wasm-function[$sSa13JavaScriptKitAA20ConvertibleToJSValue_pRszlE15withRawJSValuesyqd__qd__SaySo0hF0aGXElF01_ghI0L_yqd0__SayAaB_pG_SiAFzqd0__AFXEtAaB_pRszr___lFqd0__AEXEfU_TA]
	<?>.wasm-function[$s13JavaScriptKit7JSValueO07withRawD0yxxSo0fD0aXElF]
	<?>.wasm-function[$sSa13JavaScriptKitAA20ConvertibleToJSValue_pRszlE15withRawJSValuesyqd__qd__SaySo0hF0aGXElF01_ghI0L_yqd0__SayAaB_pG_SiAFzqd0__AFXEtAaB_pRszr___lF]
	<?>.wasm-function[$sSa13JavaScriptKitAA20ConvertibleToJSValue_pRszlE15withRawJSValuesyqd__qd__SaySo0hF0aGXElF]
	<?>.wasm-function[$s13JavaScriptKit27invokeNonThrowingJSFunction_9arguments4thisSo10RawJSValueaAA0G0C_SayAA013ConvertibleToK0_pGAA8JSObjectCSgtF]
	<?>.wasm-function[$s13JavaScriptKit10JSFunctionC14callAsFunction4this9argumentsAA7JSValueOAA8JSObjectCSg_SayAA013ConvertibleToJ0_pGtF]
	<?>.wasm-function[$s13JavaScriptKit8JSObjectCyAA7JSValueOAA013ConvertibleToE0_pd_tcSgSScigAeaF_pd_tcfU_]
	<?>.wasm-function[$s13JavaScriptKit8JSObjectCyAA7JSValueOAA013ConvertibleToE0_pd_tcSgSScigAeaF_pd_tcfU_TA]
	<?>.wasm-function[$s10TokamakDOM16DOMFiberRendererV6commityySay0A4Core8MutationOyACGGF]
	<?>.wasm-function[$s10TokamakDOM16DOMFiberRendererV0A4Core05FiberD0AadEP6commityySayAD8MutationOyxGGFTW]
	<?>.wasm-function[$s11TokamakCore15FiberReconcilerC9reconcileyyF]
	<?>.wasm-function[$s11TokamakCore15FiberReconcilerC12fiberChangedyyAC0C0Cyx_GFyycfU_]
	<?>.wasm-function[$s11TokamakCore15FiberReconcilerC12fiberChangedyyAC0C0Cyx_GFyycfU_TA]
	<?>.wasm-function[$s13OpenCombineJS11JSSchedulerC8schedule7options_yAC16SchedulerOptionsVSg_yyctFyycfU_]
	<?>.wasm-function[$s13OpenCombineJS11JSSchedulerC8schedule7options_yAC16SchedulerOptionsVSg_yyctFyycfU_TA]
	<?>.wasm-function[$s13JavaScriptKit7JSTimerC17millisecondsDelay11isRepeating8callbackACSd_SbyyctcfcAA7JSValueOSayAHGcfU0_]
	<?>.wasm-function[$s13JavaScriptKit7JSTimerC17millisecondsDelay11isRepeating8callbackACSd_SbyyctcfcAA7JSValueOSayAHGcfU0_TA]
	<?>.wasm-function[$s13JavaScriptKit16JSOneshotClosureC_4file4lineAcA7JSValueOSayAGGc_SSs6UInt32VtcfcAgHcfU0_]
	<?>.wasm-function[$s13JavaScriptKit16JSOneshotClosureC_4file4lineAcA7JSValueOSayAGGc_SSs6UInt32VtcfcAgHcfU0_TA]
	<?>.wasm-function[$sSay13JavaScriptKit7JSValueOGACIeggo_AdCIegnr_TR]
	<?>.wasm-function[$sSay13JavaScriptKit7JSValueOGACIeggo_AdCIegnr_TRTA]
	<?>.wasm-function[$sSay13JavaScriptKit7JSValueOGACIegnr_AdCIeggo_TR]
	<?>.wasm-function[$sSay13JavaScriptKit7JSValueOGACIegnr_AdCIeggo_TRTA]
	<?>.wasm-function[$s13JavaScriptKit24_call_host_function_implySbs6UInt32V_SPySo10RawJSValueaGs5Int32VADtF]
	<?>.wasm-function[_call_host_function_impl]
	<?>.wasm-function[swjs_call_host_function]
	wasm-stub
	callHostFunction (index.mjs:404)

[gregcotten]

@carson-katri what's it gonna take to merge this in?

[carson-katri]

@ahti Is this superseded by #525?

[ahti]

While #525 does also contain this change, I think merging this as-is would be fine. Fixing the parameter order is a strict improvement imo and I did have a case or two where this was the only issue preventing them from working.

[carson-katri]

Ok, merged as-is. You'll probably get a conflict on #525 now.