Use .def for function exports (#625)

Cherry-picked from primedev

Co-authored-by: F1F7Y <filip.bartos07@proton.me>

primedev/Northstar.cmake

@@ -150,8 +150,8 @@ add_library(
     "util/wininfo.cpp"
     "util/wininfo.h"
     "dllmain.cpp"
-    "dllmain.h"
     "ns_version.h"
+    "Northstar.def"
     )
 
 target_link_libraries(

primedev/Northstar.def

@@ -0,0 +1,4 @@
+LIBRARY dedicated
+
+EXPORTS
+    InitialiseNorthstar @1

primedev/dllmain.cpp

@@ -1,4 +1,3 @@
-#include "dllmain.h"
 #include "logging/logging.h"
 #include "logging/crashhandler.h"
 #include "core/memalloc.h"

primedev/dllmain.h

@@ -1,3 +0,0 @@
-#pragma once
-
-extern "C" __declspec(dllexport) bool InitialiseNorthstar();