Pretty much almost all commercially available HDL/V simulators (QuestaSim, Active-HDL, Riviera, VCS, NC-Sim, etc.) support PLS and SVA. The range of constructs that they support varies from one to another (usually you have to refer to their documentations.) But overall, QuestaSim seems to be ahead of the game. I may be wrong here.
I am not aware of a free edition of any of products that support PLS/SVA. I am also interested to know if there is any.
Regards,