move widestrs out of system (#20462)

* move widestrs out of system

* fix osproc

tests/arc/t19862.nim

@@ -2,6 +2,8 @@ discard """
   matrix: "--gc:refc; --gc:arc"
 """
 
+import std/widestrs
+
 # bug #19862
 type NewString = object
 

tests/ccgbugs/tcgbug.nim

@@ -24,6 +24,7 @@ q(a)
 
 # bug #914
 when defined(windows):
+  import std/widestrs
   var x = newWideCString("Hello")
 
 echo "success"

tests/effects/tstrict_funcs_imports.nim

@@ -7,6 +7,15 @@ discard """
 when defined(linux):
   import linenoise
 
+when defined(nimPreviewSlimSystem):
+  import std/[
+    assertions,
+    formatfloat,
+    objectdollar,
+    syncio,
+    widestrs,
+  ]
+
 import
   algorithm,
   asyncdispatch,

tests/js/tstdlib_imports.nim

@@ -4,6 +4,11 @@ discard """
 
 {.warning[UnusedImport]: off.}
 
+when defined(nimPreviewSlimSystem):
+  import std/[
+    syncio, assertions, formatfloat, objectdollar, widestrs
+  ]
+
 import std/[
   # Core:
   bitops, typetraits, lenientops, macros, volatile, typeinfo,

tests/stdlib/t15663.nim

@@ -3,5 +3,7 @@ discard """
   output: "Test"
 """
 
+import std/widestrs
+
 let ws = newWideCString("Test")
-echo ws
+echo ws

tests/stdlib/tenvvars.nim

@@ -49,6 +49,7 @@ template main =
 main()
 
 when defined(windows):
+  import std/widestrs
   proc c_wgetenv(env: WideCString): WideCString {.importc: "_wgetenv", header: "<stdlib.h>".}
 proc c_getenv(env: cstring): cstring {.importc: "getenv", header: "<stdlib.h>".}
 

tests/stdlib/tosenv.nim

@@ -50,6 +50,7 @@ static: main()
 main()
 
 when defined(windows):
+  import std/widestrs
   proc c_wgetenv(env: WideCString): WideCString {.importc: "_wgetenv", header: "<stdlib.h>".}
 proc c_getenv(env: cstring): cstring {.importc: "getenv", header: "<stdlib.h>".}
 

tests/stdlib/twchartoutf8.nim

@@ -10,6 +10,7 @@ import std/[syncio, assertions]
 when not defined(windows):
   echo "OK"
 else:
+  import std/widestrs
   {.push gcsafe.}
 
   const CP_UTF8 = 65001'i32

tests/test_nimscript.nims

@@ -6,7 +6,9 @@
 from stdtest/specialpaths import buildDir
 
 when defined(nimPreviewSlimSystem):
-  import std/syncio
+  import std/[
+    syncio, assertions, formatfloat, objectdollar, widestrs
+  ]
 
 import std/[
   # Core: