[RogueC] Fixed code-culling bug in property modify-and-assign.
[RogueC] Fixed code-culling bug in property modify-and-assign.

- CmdModifyAndAssignProperty operation 'context' was not being visited in visitor.

Plasmaworks/Rogue,Plasmaworks/Rogue,Plasmaworks/Rogue,AbePralle/Rogue,AbePralle/Rogue,Plasmaworks/Rogue