If you must disable interrupts (Shouldn't need to) then you can disable individual interrupts with their flags. In your previous thread you asked why I did if(RCIF && RCIE) and this is exactly why I do that. If you turn of interrupts by clearing RCIE and the external interrupt is triggered by the PIR then the UART code can still be executed even though disabled.
If you must disable interrupts (Shouldn't need to) then you can disable individual interrupts with their flags. In your previous thread you asked why I did if(RCIF && RCIE) and this is exactly why I do that. If you turn of interrupts by clearing RCIE and the external interrupt is triggered by the PIR then the UART code can still be executed even though disabled.