[std/os clean up] import and export osseps (#20580)

import and export osseps

doc/intern.md

@@ -364,7 +364,7 @@ Files that may need changed for your platform include:
   Add os/cpu to `Project.Platforms` field.
 * `lib/system/platforms.nim`
   Add os/cpu.
-* `lib/pure/include/osseps.nim`
+* `std/private/osseps.nim`
   Add os specializations.
 * `lib/pure/distros.nim`
   Add os, package handler.

lib/pure/os.nim

@@ -95,7 +95,8 @@ type
 
   OSErrorCode* = distinct int32 ## Specifies an OS Error Code.
 
-include "includes/osseps"
+import std/private/osseps
+export osseps
 
 proc absolutePathInternal(path: string): string {.gcsafe.}
 

lib/pure/pathnorm.nim

@@ -14,7 +14,7 @@
 
 # Yes, this uses import here, not include so that
 # we don't end up exporting these symbols from pathnorm and os:
-import includes/osseps
+import std/private/osseps
 
 type
   PathIter* = object