Tolk: `originalForwardFee` hardcodes workchain 0, breaks on masterchain

[Gusarich]

The InMessage.originalForwardFee accessor hardcodes workchain 0 when calling GETORIGINALFWDFEE, producing incorrect results for contracts deployed on masterchain.

fun onInternalMessage(in: InMessage): coins {
    return in.originalForwardFee;
}

Compiles to:

PROGRAM{
  0 DECLMETHOD onInternalMessage()
  onInternalMessage() PROC:<{  //  in.body
    DROP
    INMSG_BOUNCED
    0 THROWIF
    INMSG_FWDFEE
    0 PUSHINT
    GETORIGINALFWDFEE
  }>
}END>c

The GETORIGINALFWDFEE instruction requires the workchain to compute the original fee based on that chain's fee configuration. Masterchain (workchain -1) has significantly higher fees than basechain (workchain 0).

A contract on masterchain using in.originalForwardFee will receive basechain fee calculations instead, causing incorrect fee accounting and potentially under-reserving funds for message forwarding.