8285730: unify _WIN32_WINNT settings

Reviewed-by: dholmes, erikj, ihse, prr, alanb

make/autoconf/flags-cflags.m4

@@ -457,9 +457,11 @@ AC_DEFUN([FLAGS_SETUP_CFLAGS_HELPER],
     ALWAYS_DEFINES_JVM="-D_REENTRANT"
     ALWAYS_DEFINES_JDK="-D_GNU_SOURCE -D_REENTRANT -D_LARGEFILE64_SOURCE -DSTDC"
   elif test "x$TOOLCHAIN_TYPE" = xmicrosoft; then
-    ALWAYS_DEFINES_JDK="-DWIN32_LEAN_AND_MEAN -D_CRT_SECURE_NO_DEPRECATE \
+    # Access APIs for Windows 8 and above
+    # see https://docs.microsoft.com/en-us/cpp/porting/modifying-winver-and-win32-winnt?view=msvc-170
+    ALWAYS_DEFINES_JDK="-DWIN32_LEAN_AND_MEAN -D_WIN32_WINNT=0x0602 -D_CRT_SECURE_NO_DEPRECATE \
         -D_CRT_NONSTDC_NO_DEPRECATE -DWIN32 -DIAL"
-    ALWAYS_DEFINES_JVM="-DNOMINMAX -DWIN32_LEAN_AND_MEAN"
+    ALWAYS_DEFINES_JVM="-DNOMINMAX -DWIN32_LEAN_AND_MEAN -D_WIN32_WINNT=0x0602"
   fi
 
   ###############################################################################

src/hotspot/os/windows/os_windows.cpp

@@ -22,8 +22,7 @@
  *
  */
 
-// Must be at least Windows Vista or Server 2008 to use InitOnceExecuteOnce
-#define _WIN32_WINNT 0x0600
+// API level must be at least Windows Vista or Server 2008 to use InitOnceExecuteOnce
 
 // no precompiled headers
 #include "jvm.h"

src/java.base/windows/native/libjava/WinCAPISeedGenerator.c

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2002, 2014, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2002, 2022, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -23,11 +23,6 @@
  * questions.
  */
 
-/* Need to define this to get CAPI functions included */
-#ifndef _WIN32_WINNT
-#define _WIN32_WINNT 0x0400
-#endif
-
 #include <windows.h>
 #include <wincrypt.h>
 #include <jni.h>

src/java.base/windows/native/libjava/WinNTFileSystem_md.c

@@ -23,11 +23,6 @@
  * questions.
  */
 
-/* Access APIs for WinXP and above */
-#ifndef _WIN32_WINNT
-#define _WIN32_WINNT 0x0501
-#endif
-
 #include <assert.h>
 #include <stdio.h>
 #include <stdlib.h>

src/java.base/windows/native/libjava/java_props_md.c

@@ -23,11 +23,6 @@
  * questions.
  */
 
-/* Access APIs for Windows Vista and above */
-#ifndef _WIN32_WINNT
-#define _WIN32_WINNT 0x0601
-#endif
-
 #include "jni.h"
 #include "jni_util.h"
 

src/java.desktop/windows/native/libawt/windows/awt.h

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 1996, 2014, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 1996, 2022, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -26,10 +26,6 @@
 #ifndef _AWT_H_
 #define _AWT_H_
 
-#ifndef _WIN32_WINNT
-#define _WIN32_WINNT 0x0600
-#endif
-
 #ifndef _WIN32_IE
 #define _WIN32_IE 0x0600
 #endif

src/java.desktop/windows/native/libsplashscreen/splashscreen_sys.c

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2005, 2019, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2005, 2022, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -23,11 +23,6 @@
  * questions.
  */
 
-// copy from awt.h
-#ifndef _WIN32_WINNT
-#define _WIN32_WINNT 0x0600
-#endif
-
 // copy from awt.h
 #ifndef _WIN32_IE
 #define _WIN32_IE 0x0600