clean up std/os related modules (#20651)

* clean up `std/os` related modules

* use `cmpPaths`

* reset

* cleanup

lib/std/private/oscommon.nim

@@ -1,6 +1,5 @@
 include system/inclrtl
 
-import ospaths2
 import std/[oserrors]
 
 when defined(nimPreviewSlimSystem):
@@ -9,6 +8,15 @@ when defined(nimPreviewSlimSystem):
 const weirdTarget* = defined(nimscript) or defined(js)
 
 
+type
+  ReadDirEffect* = object of ReadIOEffect   ## Effect that denotes a read
+                                            ## operation from the directory
+                                            ## structure.
+  WriteDirEffect* = object of WriteIOEffect ## Effect that denotes a write
+                                            ## operation to
+                                            ## the directory structure.
+
+
 when weirdTarget:
   discard
 elif defined(windows):
@@ -181,3 +189,23 @@ proc symlinkExists*(link: string): bool {.rtl, extern: "nos$1",
   else:
     var res: Stat
     result = lstat(link, res) >= 0'i32 and S_ISLNK(res.st_mode)
+
+when defined(windows) and not weirdTarget:
+  proc openHandle*(path: string, followSymlink=true, writeAccess=false): Handle =
+    var flags = FILE_FLAG_BACKUP_SEMANTICS or FILE_ATTRIBUTE_NORMAL
+    if not followSymlink:
+      flags = flags or FILE_FLAG_OPEN_REPARSE_POINT
+    let access = if writeAccess: GENERIC_WRITE else: 0'i32
+
+    when useWinUnicode:
+      result = createFileW(
+        newWideCString(path), access,
+        FILE_SHARE_DELETE or FILE_SHARE_READ or FILE_SHARE_WRITE,
+        nil, OPEN_EXISTING, flags, 0
+        )
+    else:
+      result = createFileA(
+        path, access,
+        FILE_SHARE_DELETE or FILE_SHARE_READ or FILE_SHARE_WRITE,
+        nil, OPEN_EXISTING, flags, 0
+        )