target  : (0,0x62) IStDarg
status  : emitted
from    : discovery snippet 'darg_optional_byref' (minimised)

' ---- modProbe.bas
Option Explicit

Public Sub Main()
  
End Sub

Sub P(Optional x As Variant)
  Dim n As Long
  n = x
  x = 1
  If IsMissing(x) Then n = 2
End Sub

target disasm lines:
  modProbe.Proc_4014B4 | 4014C4    62 0C00               IStDarg arg_C
