let align_of_builtin_type = 
  function
      Tchar | Tuchar | Tschar ->  sizeof_char
    | Tshort | Tushort ->  sizeof_short
    | Tint | Tuint ->  sizeof_int
    | Tlong | Tulong ->  sizeof_long
    | Tlonglong | Tulonglong ->  sizeof_longlong
    | Tfloat ->  sizeof_float
    | Tdouble ->  sizeof_double
    | Tlongdouble -> sizeof_longdouble