AnyStr cleanup (#5487)

* Replace all uses of StrPath, BytesPath, and AnyPath in Python 2 stubs.
* Add StrOrBytesPath as preferred alias for AnyPath.
* Replace all remaining AnyPath instances with StrOrBytesPath.
* Mark AnyPath as obsolete.

Part of #5470

stdlib/genericpath.pyi

@@ -1,5 +1,5 @@
 import os
-from _typeshed import AnyPath, BytesPath, StrPath, SupportsLessThanT
+from _typeshed import BytesPath, StrOrBytesPath, StrPath, SupportsLessThanT
 from typing import List, Sequence, Tuple, Union, overload
 from typing_extensions import Literal
 
@@ -14,16 +14,16 @@ def commonprefix(m: Sequence[BytesPath]) -> Union[bytes, Literal[""]]: ...
 def commonprefix(m: Sequence[List[SupportsLessThanT]]) -> Sequence[SupportsLessThanT]: ...
 @overload
 def commonprefix(m: Sequence[Tuple[SupportsLessThanT, ...]]) -> Sequence[SupportsLessThanT]: ...
-def exists(path: AnyPath) -> bool: ...
-def getsize(filename: AnyPath) -> int: ...
-def isfile(path: AnyPath) -> bool: ...
-def isdir(s: AnyPath) -> bool: ...
+def exists(path: StrOrBytesPath) -> bool: ...
+def getsize(filename: StrOrBytesPath) -> int: ...
+def isfile(path: StrOrBytesPath) -> bool: ...
+def isdir(s: StrOrBytesPath) -> bool: ...
 
 # These return float if os.stat_float_times() == True,
 # but int is a subclass of float.
-def getatime(filename: AnyPath) -> float: ...
-def getmtime(filename: AnyPath) -> float: ...
-def getctime(filename: AnyPath) -> float: ...
-def samefile(f1: AnyPath, f2: AnyPath) -> bool: ...
+def getatime(filename: StrOrBytesPath) -> float: ...
+def getmtime(filename: StrOrBytesPath) -> float: ...
+def getctime(filename: StrOrBytesPath) -> float: ...
+def samefile(f1: StrOrBytesPath, f2: StrOrBytesPath) -> bool: ...
 def sameopenfile(fp1: int, fp2: int) -> bool: ...
 def samestat(s1: os.stat_result, s2: os.stat_result) -> bool: ...