[Sdb] Ignore hidden sequence points

Hidden sequence points are created by Roslyn or csc.exe + pdb2mdb...
We could stop emitting them in pdb2mdb and Roslyn but prefer to do this in runtime for two reasons:
* We would need to worry about syncing modified pdb2mdb with runtime
* Maybe we will want to use this hidden sequence points in future inside Runtime and we will have to modify pdb2mdb again...
This depends on method and not assembly. It depends on number of ILs(Sequence points to be more exact) It can be up thousand(or more) approximately 2 per line(and methods can be 500 lines+ in some cases...)