move widestrs out of system (#20462)

* move widestrs out of system

* fix osproc

lib/pure/asyncfile.nim

@@ -26,6 +26,8 @@ import asyncdispatch, os
 
 when defined(nimPreviewSlimSystem):
   import std/[assertions, syncio]
+  when defined(windows):
+    import std/widestrs
 
 # TODO: Fix duplication introduced by PR #4683.
 

lib/pure/browsers.nim

@@ -21,6 +21,8 @@ when defined(nimPreviewSlimSystem):
 
 when defined(windows):
   import winlean
+  when useWinUnicode and defined(nimPreviewSlimSystem):
+    import std/widestrs
   from os import absolutePath
 else:
   import os

lib/pure/includes/osenv.nim

@@ -43,6 +43,8 @@ when not defined(nimscript):
   else:
 
     when defined(windows):
+      when defined(nimPreviewSlimSystem):
+        import std/widestrs
       proc c_putenv(envstring: cstring): cint {.importc: "_putenv", header: "<stdlib.h>".}
       from std/private/win_setenv import setEnvImpl
       proc c_wgetenv(varname: WideCString): WideCString {.importc: "_wgetenv",

lib/pure/includes/oserr.nim

@@ -11,6 +11,8 @@ when not defined(nimscript):
 
   when defined(windows):
     import winlean
+    when useWinUnicode and defined(nimPreviewSlimSystem):
+      import std/widestrs
 
 proc `==`*(err1, err2: OSErrorCode): bool {.borrow.}
 proc `$`*(err: OSErrorCode): string {.borrow.}

lib/pure/memfiles.nim

@@ -17,6 +17,8 @@
 
 when defined(windows):
   import winlean
+  when useWinUnicode and defined(nimPreviewSlimSystem):
+    import std/widestrs
 elif defined(posix):
   import posix
 else:

lib/pure/os.nim

@@ -968,6 +968,9 @@ proc getCacheDir*(app: string): string =
 when defined(windows):
   type DWORD = uint32
 
+  when defined(nimPreviewSlimSystem):
+    import std/widestrs
+
   proc getTempPath(
     nBufferLength: DWORD, lpBuffer: WideCString
   ): DWORD {.stdcall, dynlib: "kernel32.dll", importc: "GetTempPathW".} =

lib/pure/osproc.nim

@@ -33,6 +33,8 @@ when defined(linux) and defined(useClone):
 
 when defined(nimPreviewSlimSystem):
   import std/[syncio, assertions]
+  when defined(windows):
+    import std/widestrs
 
 
 type