Add typestubs for the warnings module (#3543)

stdlib/2and3/warnings.pyi

@@ -1,4 +1,5 @@
-from typing import List, NamedTuple, Optional, overload, TextIO, Type
+import sys
+from typing import Any, List, NamedTuple, Optional, overload, TextIO, Type
 from types import ModuleType, TracebackType
 from typing_extensions import Literal
 
@@ -14,13 +15,20 @@ def filterwarnings(
 def simplefilter(action: str, category: Type[Warning] = ..., lineno: int = ..., append: bool = ...) -> None: ...
 def resetwarnings() -> None: ...
 
-class _Record(NamedTuple):
-    message: str
+class _OptionError(Exception): ...
+
+class WarningMessage:
+    message: Warning
     category: Type[Warning]
-    filename: str
-    lineno: int
-    file: Optional[TextIO]
-    line: Optional[str]
+    filename: Any
+    lineno: Any
+    file: Optional[Any]
+    line: Optional[Any]
+    if sys.version_info >= (3, 6):
+        source: Optional[Any]
+        def __init__(self, message: Warning, category: Type[Warning], filename: Any, lineno: Any, file: Optional[Any] = ..., line: Optional[Any] = ..., source: Optional[Any] = ...) -> None: ...
+    else:
+        def __init__(self, message: Warning, category: Type[Warning], filename: Any, lineno: Any, file: Optional[Any] = ..., line: Optional[Any] = ...) -> None: ...
 
 class catch_warnings:
     @overload
@@ -29,7 +37,7 @@ class catch_warnings:
     def __new__(cls, *, record: Literal[True], module: Optional[ModuleType] = ...) -> _catch_warnings_with_records: ...
     @overload
     def __new__(cls, *, record: bool, module: Optional[ModuleType] = ...) -> catch_warnings: ...
-    def __enter__(self) -> Optional[List[_Record]]: ...
+    def __enter__(self) -> Optional[List[WarningMessage]]: ...
     def __exit__(
         self, exc_type: Optional[Type[BaseException]], exc_val: Optional[BaseException], exc_tb: Optional[TracebackType]
     ) -> None: ...
@@ -38,4 +46,4 @@ class _catch_warnings_without_records(catch_warnings):
     def __enter__(self) -> None: ...
 
 class _catch_warnings_with_records(catch_warnings):
-    def __enter__(self) -> List[_Record]: ...
+    def __enter__(self) -> List[WarningMessage]: ...