The gas cost of invocation of that host call.
NOTE: ((reg: HostCallRegisters) => Gas) function is for compatibility reasons: pre GP 0.7.2
ReadonlycurrentCurrently executing service id.
Index of that host call (i.e. what PVM invokes via ecalli)
Input&Output registers that we should add to tracing log.
Actually execute the host call.
NOTE the call is ALLOWED and expected to modify registers and memory.
Modify privileged services and services that auto-accumulate every block.
https://graypaper.fluffylabs.dev/#/7e6ff6a/363b00363b00?v=0.6.7