Mark the following compatability system calls as MCOMPAT or MCOMPAT4 based

Mark the following compatability system calls as MCOMPAT or MCOMPAT4 based
on the their simply wrapping MPSAFE implementations of existing MPSAFE
system calls:

  getfsstat()
  lseek()
  stat()
  lstat()
  truncate()
  ftruncate()
  statfs()
  fstatfs()

Note that ogetdirentries() is not marked MPSAFE because it does not share
the MPSAFE implementation used for getdirentries(), and requires separate
locking to be implemented.