illumos gate

While going through 7094, I found that Pgrab_idle tries to construct the full path of the object. However, it often can't construct it because the actual size of the field is limited to 64 bytes, which comes from the assumption that it always comes from a prmap_t from /proc. Instead, we should increase this to PATH_MAX so that way when we're referring to files in the file system, we'll actually be able to find them.