Add stubs for the faulthandler stdlib module (#2627)

stdlib/3/faulthandler.pyi

@@ -0,0 +1,23 @@
+import sys
+from typing import Union, Protocol
+
+
+class _HasFileno(Protocol):
+    def fileno(self) -> int: ...
+
+
+if sys.version_info >= (3, 5):
+    _File = Union[_HasFileno, int]
+else:
+    _File = _HasFileno
+
+
+def cancel_dump_traceback_later() -> None: ...
+def disable() -> None: ...
+def dump_traceback(file: _File = ..., all_threads: bool = ...) -> None: ...
+def dump_traceback_later(timeout: int, repeat: bool = ..., file: _File = ..., exit: bool = ...) -> None: ...
+def enable(file: _File = ..., all_threads: bool = ...) -> None: ...
+def is_enabled() -> bool: ...
+if sys.platform != "win32":
+    def register(signum: int, file: _File = ..., all_threads: bool = ..., chain: bool = ...) -> None: ...
+    def unregister(signum: int) -> None: ...