remove unused imports

lib/pure/concurrency/cpuinfo.nim

@@ -12,10 +12,7 @@
 include "system/inclrtl"
 
 when not defined(windows):
-  import strutils, posix, os
-
-when defined(linux):
-  import linux
+  import posix
 
 when defined(freebsd) or defined(macosx):
   {.emit:"#include <sys/types.h>".}

lib/pure/includes/osenv.nim

@@ -3,7 +3,8 @@
 when not declared(os) and not declared(ospaths):
   {.error: "This is an include file for os.nim!".}
 
-from parseutils import skipIgnoreCase
+when defined(windows):
+  from parseutils import skipIgnoreCase
 
 proc c_getenv(env: cstring): cstring {.
   importc: "getenv", header: "<stdlib.h>".}

lib/pure/osproc.nim

@@ -27,9 +27,6 @@ when defined(windows):
 else:
   import posix
 
-when defined(linux):
-  import linux
-
 type
   ProcessOption* = enum ## Options that can be passed to `startProcess proc
                         ## <#startProcess,string,string,openArray[string],StringTableRef,set[ProcessOption]>`_.

lib/pure/parseopt.nim

@@ -151,8 +151,7 @@
 
 include "system/inclrtl"
 
-import
-  os, strutils
+import os
 
 type
   CmdLineKind* = enum ## The detected command line token.