add std/private/win_getsysteminfo; refactor the usage of `GetSystemInfo` (#19310)

* add std/private/win_getsysteminfo

* import at the top level

* wrappers follow nep1 too

* follow review comment

2 files changed, 8 insertions, 35 deletions

diff --git a/lib/pure/concurrency/cpuinfo.nim b/lib/pure/concurrency/cpuinfo.nim
index ee43b8e11..16d32002d 100644
--- a/lib/pure/concurrency/cpuinfo.nim
+++ b/lib/pure/concurrency/cpuinfo.nim
@@ -18,6 +18,9 @@ include "system/inclrtl"
 when defined(posix) and not (defined(macosx) or defined(bsd)):
   import posix
 
+when defined(windows):
+  import std/private/win_getsysteminfo
+
 when defined(freebsd) or defined(macosx):
   {.emit: "#include <sys/types.h>".}
 
@@ -54,25 +57,10 @@ proc countProcessors*(): int {.rtl, extern: "ncpi$1".} =
   ## Returns the number of the processors/cores the machine has.
   ## Returns 0 if it cannot be detected.
   when defined(windows):
-    type
-      SYSTEM_INFO {.final, pure.} = object
-        u1: int32
-        dwPageSize: int32
-        lpMinimumApplicationAddress: pointer
-        lpMaximumApplicationAddress: pointer
-        dwActiveProcessorMask: ptr int32
-        dwNumberOfProcessors: int32
-        dwProcessorType: int32
-        dwAllocationGranularity: int32
-        wProcessorLevel: int16
-        wProcessorRevision: int16
-
-    proc GetSystemInfo(lpSystemInfo: var SYSTEM_INFO) {.stdcall, dynlib: "kernel32", importc: "GetSystemInfo".}
-
     var
-      si: SYSTEM_INFO
-    GetSystemInfo(si)
-    result = si.dwNumberOfProcessors
+      si: SystemInfo
+    getSystemInfo(addr si)
+    result = int(si.dwNumberOfProcessors)
   elif defined(macosx) or defined(bsd):
     var
       mib: array[0..3, cint]
diff --git a/lib/pure/reservedmem.nim b/lib/pure/reservedmem.nim
index 232a2b383..99fbe1429 100644
--- a/lib/pure/reservedmem.nim
+++ b/lib/pure/reservedmem.nim
@@ -42,25 +42,10 @@ type
 
 when defined(windows):
   import winlean
-
-  type
-    SYSTEM_INFO {.final, pure.} = object
-      u1: uint32
-      dwPageSize: uint32
-      lpMinimumApplicationAddress: pointer
-      lpMaximumApplicationAddress: pointer
-      dwActiveProcessorMask: ptr uint32
-      dwNumberOfProcessors: uint32
-      dwProcessorType: uint32
-      dwAllocationGranularity: uint32
-      wProcessorLevel: uint16
-      wProcessorRevision: uint16
-
-  proc getSystemInfo(lpSystemInfo: ptr SYSTEM_INFO) {.stdcall,
-      dynlib: "kernel32", importc: "GetSystemInfo".}
+  import std/private/win_getsysteminfo
 
   proc getAllocationGranularity: uint =
-    var sysInfo: SYSTEM_INFO
+    var sysInfo: SystemInfo
     getSystemInfo(addr sysInfo)
     return uint(sysInfo.dwAllocationGranularity)