Re: [sv-bc] @* vs. always_comb

Synthesis already handles hierarchical references just fine, including
hierarchical function calls, as long as the references are into
interface instances.

>>  As one example, synthesis does not handle
>>hierarchical references well (or at all).  Originally the
>>always_comb definition took that into account.  This became
>>so ugly that regularity was reimposed by allowing hierarchical
>>sensitivities even through a hierarchically called function.
>>The cost of this is significant in terms of both conceptual
>>complexity and speed of simulation.
>
>This is unfortunate, but necessary if you want to handle everything
>that synthesis could ever accept.  One way to avoid this would be
>to make hierarchical calls to functions illegal in always_comb
>blocks.

-- Brad