win32: Fix build with IPv6 disabled.

* include/arch/win32/apr_arch_misc.h:
  (if_nametoindex, if_indextoname): Declare only if HAVE_IF_NAMETOINDEX/
   HAVE_IF_INDEXTONAME.

git-svn-id: https://svn.apache.org/repos/asf/apr/apr/trunk@1902577 13f79535-47bb-0310-9956-ffa450edef68
diff --git a/include/arch/win32/apr_arch_misc.h b/include/arch/win32/apr_arch_misc.h
index 057f4ad..fb5bb61 100644
--- a/include/arch/win32/apr_arch_misc.h
+++ b/include/arch/win32/apr_arch_misc.h
@@ -267,6 +267,7 @@
 
 #define HAVE_POLL   1
 
+#if HAVE_IF_NAMETOINDEX
 #ifdef if_nametoindex
 #undef if_nametoindex
 #endif
@@ -274,7 +275,9 @@
     IN PCSTR InterfaceName),
     (InterfaceName));
 #define if_nametoindex apr_winapi_if_nametoindex
+#endif
 
+#if HAVE_IF_INDEXTONAME
 #ifdef if_indextoname
 #undef if_indextoname
 #endif
@@ -283,6 +286,7 @@
     PCHAR       InterfaceName),
     (InterfaceIndex, InterfaceName));
 #define if_indextoname apr_winapi_if_indextoname
+#endif
 
 APR_DECLARE_LATE_DLL_FUNC(DLL_API_MS_WIN_DOWNLEVEL_SHELL32_L1_1_0, LPWSTR *,
                           STDAPICALLTYPE, CommandLineToArgvW, 0,