Windows: extend WinSDK module further

This extends the WinSDK modulemap to cover Winsock2 and IPHelp API Set.
These are used in Foundation.

Author: compnerd

stdlib/public/Platform/winsdk.modulemap

@@ -11,6 +11,12 @@
 //===----------------------------------------------------------------------===//
 
 module WinSDK [system] [extern_c] {
+  module WinSock2 {
+    header "WinSock2.h"
+    header "WS2tcpip.h"
+    export *
+  }
+
   module core {
     // api-ms-win-core-errhandling-l1-1-0.dll
     module errhandling {
@@ -42,6 +48,11 @@ module WinSDK [system] [extern_c] {
       export *
     }
 
+    module iphlp {
+      header "iphlpapi.h"
+      export *
+    }
+
     // api-ms-win-core-libloader-l1-1-0.dll
     module libloader {
       header "libloaderapi.h"