Hi,

This patch expands the recently-added cgen model support for cgen-cpu to 
handle generic VLIW issues.  It accumulates the maximum number of cycles 
used by all insns in a VLIW bundle and then calls a virtual function 
(step_latency) to allow the cpu to account for those cycles.

Tested against our internal port but generally useful for other 
architectures.

ok to commit?

Dave