[DELAYIMP] Separate hook symbols from library code

This allows to define these functions in the importing module.

sdk/lib/delayimp/CMakeLists.txt

@@ -1,5 +1,9 @@
 
 add_definitions(-DUNICODE -D_UNICODE)
-add_library(delayimp delayimp.c)
+add_library(delayimp
+    delayimp.c
+    pfnDliFailureHook2.c
+    pfnDliNotifyHook2.c
+)
 add_dependencies(delayimp psdk)
 add_importlibs(delayimp kernel32)

sdk/lib/delayimp/delayimp.c

@@ -14,8 +14,8 @@
 /**** Linker magic: provide a default (NULL) pointer, but allow the user to override it ****/
 
 /* The actual items we use */
-PfnDliHook __pfnDliNotifyHook2;
-PfnDliHook __pfnDliFailureHook2;
+extern PfnDliHook __pfnDliNotifyHook2;
+extern PfnDliHook __pfnDliFailureHook2;
 
 #if !defined(__GNUC__)
 /* The fallback symbols */

sdk/lib/delayimp/pfnDliFailureHook2.c

@@ -0,0 +1,11 @@
+/*
+ * PROJECT:     ReactOS delayimport Library
+ * LICENSE:     MIT (https://spdx.org/licenses/MIT)
+ * PURPOSE:     __pfnDliFailureHook2 symbol for delayimport library
+ * COPYRIGHT:   Copyright 2025 Timo Kreuzer <timo.kreuzer@reactos.org>
+ */
+
+#include <windef.h>
+#include <delayimp.h>
+
+PfnDliHook __pfnDliFailureHook2;

sdk/lib/delayimp/pfnDliNotifyHook2.c

@@ -0,0 +1,11 @@
+/*
+ * PROJECT:     ReactOS delayimport Library
+ * LICENSE:     MIT (https://spdx.org/licenses/MIT)
+ * PURPOSE:     __pfnDliNotifyHook2 symbol for delayimport library
+ * COPYRIGHT:   Copyright 2025 Timo Kreuzer <timo.kreuzer@reactos.org>
+ */
+
+#include <windef.h>
+#include <delayimp.h>
+
+PfnDliHook __pfnDliNotifyHook2;