[wing] build: require Windows 7+

[Ignacio Casal Quinteiro <icq src gnome org>]

commit ac435e234154a5c06360a24d0d78ecfe0718648b
Author: Jakub Janků <jjanku redhat com>
Date:   Wed Mar 25 20:22:20 2020 +0100

    build: require Windows 7+
    
    Explicitly set _WIN32_WINNT to 0x0601.
    According to [0], MSVC compiler does this by default,
    but MinGW uses 0x502 - aka Windows Server 2003.
    
    This is necessary because wing uses functions
    in threadpoolapiset.h which are first available in 0x0600.
    
    [0] https://docs.microsoft.com/en-us/cpp/porting/modifying-winver-and-win32-winnt?view=vs-2019
    
    Signed-off-by: Jakub Janků <jjanku redhat com>

 meson.build  | 1 +
 tests/poll.c | 2 --
 2 files changed, 1 insertion(+), 2 deletions(-)
---
diff --git a/meson.build b/meson.build
index bafbdfb..3cdd1ad 100644
--- a/meson.build
+++ b/meson.build
@@ -55,6 +55,7 @@ conf.set('includedir', wing_includedir)
 conf.set('VERSION', wing_version)
 
 add_project_arguments('-DG_LOG_USE_STRUCTURED=1', language: 'c')
+add_project_arguments('-D_WIN32_WINNT=0x0601', language: 'c')
 
 # Compiler flags
 if cc.get_id() == 'msvc'
diff --git a/tests/poll.c b/tests/poll.c
index 2e372da..8ed1586 100644
--- a/tests/poll.c
+++ b/tests/poll.c
@@ -16,8 +16,6 @@
  * along with this library; if not, see <http://www.gnu.org/licenses/>.
  */
 
-#define _WIN32_WINNT 0x0600
-
 #include <Winsock2.h>
 #include <wing/wing.h>
 #include <glib.h>