Fix RH850 vIPIR emulation

[malejo97]

The previous vIPIR emulation handler had a few issues:

• Bitwise instructions were incorrectly treated as a subset of read/write instructions.
• pCPU↔vCPU mask translation was using the number of CPUs in the current VM instead of the number of CPUs in the platform.
• Read operations were incorrectly translating masks back to pCPU masks instead of returning vCPU masks.

This PR fixes these issues and updates acc->arch.bit to store the actual bit mask associated with the bitwise instruction, rather than the bit index.

⚠️ Depends on #361

[danielRep]

Can you rebase this @malejo97 ?

[malejo97]

Can you rebase this @malejo97 ?

Done @danielRep