Re-organize directory structure (#4971)

See discussion in #2491

Co-authored-by: Ivan Levkivskyi <ilevkivskyi@dropbox.com>

stdlib/platform.pyi

@@ -0,0 +1,66 @@
+import sys
+
+if sys.version_info < (3, 9):
+    import os
+
+    DEV_NULL = os.devnull
+from typing import NamedTuple, Optional, Tuple
+
+if sys.version_info >= (3, 8):
+    def libc_ver(
+        executable: Optional[str] = ..., lib: str = ..., version: str = ..., chunksize: int = ...
+    ) -> Tuple[str, str]: ...
+
+else:
+    def libc_ver(executable: str = ..., lib: str = ..., version: str = ..., chunksize: int = ...) -> Tuple[str, str]: ...
+
+if sys.version_info < (3, 8):
+    def linux_distribution(
+        distname: str = ...,
+        version: str = ...,
+        id: str = ...,
+        supported_dists: Tuple[str, ...] = ...,
+        full_distribution_name: bool = ...,
+    ) -> Tuple[str, str, str]: ...
+    def dist(
+        distname: str = ..., version: str = ..., id: str = ..., supported_dists: Tuple[str, ...] = ...
+    ) -> Tuple[str, str, str]: ...
+
+def win32_ver(release: str = ..., version: str = ..., csd: str = ..., ptype: str = ...) -> Tuple[str, str, str, str]: ...
+
+if sys.version_info >= (3, 8):
+    def win32_edition() -> str: ...
+    def win32_is_iot() -> bool: ...
+
+def mac_ver(
+    release: str = ..., versioninfo: Tuple[str, str, str] = ..., machine: str = ...
+) -> Tuple[str, Tuple[str, str, str], str]: ...
+def java_ver(
+    release: str = ..., vendor: str = ..., vminfo: Tuple[str, str, str] = ..., osinfo: Tuple[str, str, str] = ...
+) -> Tuple[str, str, Tuple[str, str, str], Tuple[str, str, str]]: ...
+def system_alias(system: str, release: str, version: str) -> Tuple[str, str, str]: ...
+def architecture(executable: str = ..., bits: str = ..., linkage: str = ...) -> Tuple[str, str]: ...
+
+class uname_result(NamedTuple):
+    system: str
+    node: str
+    release: str
+    version: str
+    machine: str
+    processor: str
+
+def uname() -> uname_result: ...
+def system() -> str: ...
+def node() -> str: ...
+def release() -> str: ...
+def version() -> str: ...
+def machine() -> str: ...
+def processor() -> str: ...
+def python_implementation() -> str: ...
+def python_version() -> str: ...
+def python_version_tuple() -> Tuple[str, str, str]: ...
+def python_branch() -> str: ...
+def python_revision() -> str: ...
+def python_build() -> Tuple[str, str]: ...
+def python_compiler() -> str: ...
+def platform(aliased: bool = ..., terse: bool = ...) -> str: ...