Improve resource stubs for py3 (#1565)

Author: arturhoo

stdlib/3/resource.pyi

@@ -2,7 +2,7 @@
 
 # NOTE: These are incomplete!
 
-from typing import Tuple
+from typing import Tuple, Optional, NamedTuple
 
 RLIMIT_AS = ...  # type: int
 RLIMIT_CORE = ...  # type: int
@@ -25,7 +25,17 @@ RUSAGE_CHILDREN = ...  # type: int
 RUSAGE_SELF = ...  # type: int
 RUSAGE_THREAD = ...  # type: int
 
+_RUsage = NamedTuple('_RUsage', [('ru_utime', float), ('ru_stime', float), ('ru_maxrss', int),
+                                 ('ru_ixrss', int), ('ru_idrss', int), ('ru_isrss', int),
+                                 ('ru_minflt', int), ('ru_majflt', int), ('ru_nswap', int),
+                                 ('ru_inblock', int), ('ru_oublock', int), ('ru_msgsnd', int),
+                                 ('ru_msgrcv', int), ('ru_nsignals', int), ('ru_nvcsw', int),
+                                 ('ru_nivcsw', int)])
+
+def getpagesize() -> int: ...
 def getrlimit(resource: int) -> Tuple[int, int]: ...
+def getrusage(who: int) -> _RUsage: ...
+def prlimit(pid: int, resource: int, limits: Optional[Tuple[int, int]]) -> Tuple[int, int]: ...
 def setrlimit(resource: int, limits: Tuple[int, int]) -> None: ...
 
 # NOTE: This is an alias of OSError in Python 3.3.