Win32: Fix build on early Windows 10 SDKs

Related to #1320.

src/win32_platform.h

@@ -147,8 +147,7 @@ typedef enum
 #endif /*DPI_ENUMS_DECLARED*/
 
 #ifndef DPI_AWARENESS_CONTEXT_PER_MONITOR_AWARE_V2
-DECLARE_HANDLE(DPI_AWARENESS_CONTEXT);
-#define DPI_AWARENESS_CONTEXT_PER_MONITOR_AWARE_V2 ((DPI_AWARENESS_CONTEXT) -4)
+#define DPI_AWARENESS_CONTEXT_PER_MONITOR_AWARE_V2 ((HANDLE) -4)
 #endif /*DPI_AWARENESS_CONTEXT_PER_MONITOR_AWARE_V2*/
 
 // HACK: Define versionhelpers.h functions manually as MinGW lacks the header
@@ -225,7 +224,7 @@ typedef HRESULT (WINAPI * PFN_DirectInput8Create)(HINSTANCE,DWORD,REFIID,LPVOID*
 typedef BOOL (WINAPI * PFN_SetProcessDPIAware)(void);
 typedef BOOL (WINAPI * PFN_ChangeWindowMessageFilterEx)(HWND,UINT,DWORD,CHANGEFILTERSTRUCT*);
 typedef BOOL (WINAPI * PFN_EnableNonClientDpiScaling)(HWND);
-typedef BOOL (WINAPI * PFN_SetProcessDpiAwarenessContext)(DPI_AWARENESS_CONTEXT);
+typedef BOOL (WINAPI * PFN_SetProcessDpiAwarenessContext)(HANDLE);
 typedef UINT (WINAPI * PFN_GetDpiForWindow)(HWND);
 typedef BOOL (WINAPI * PFN_AdjustWindowRectExForDpi)(LPRECT,DWORD,BOOL,DWORD,UINT);
 #define SetProcessDPIAware _glfw.win32.user32.SetProcessDPIAware_