partially fix amd64 build on windows

Quality of this commit is questionable. I have no idea whether what I did
here makes sense or not.
But it compiles and runs (provided with hlsdk-xash3d amd64 build, which
is another story).

This omits necessary waf changes that are necessary to make a valid
64-bit build. Apparently it's not enough to just pass `-8` on Windows,
you also need to hack wscript to add `x64` target to MSVC. I'll do that
later when I figure out how.

This change is a precursor for RTX Vulkan effort --
VK_KHR_ray_tracing_pipeline and friends are only available on 64-bit
nvidia drivers (no idea about AMD, pls send GPUs onegai).

engine/platform/win32/con_win.c

@@ -354,7 +354,11 @@ void Wcon_CreateConsole( void )
 
 	if( host.type == HOST_DEDICATED )
 	{
+#ifdef XASH_64BIT
+		s_wcd.SysInputLineWndProc = (WNDPROC)SetWindowLongPtr( s_wcd.hwndInputLine, GWLP_WNDPROC, (LONG_PTR)Wcon_InputLineProc );
+#else
 		s_wcd.SysInputLineWndProc = (WNDPROC)SetWindowLong( s_wcd.hwndInputLine, GWL_WNDPROC, (long)Wcon_InputLineProc );
+#endif
 		SendMessage( s_wcd.hwndInputLine, WM_SETFONT, ( WPARAM )s_wcd.hfBufferFont, 0 );
 	}
 

engine/platform/win32/lib_win.c

@@ -20,9 +20,14 @@ GNU General Public License for more details.
 #ifdef XASH_64BIT
 #include <dbghelp.h>
 
-void *COM_LoadLibrary( const char *dllname, int build_ordinals_table )
+void *COM_LoadLibrary( const char *dllname, int build_ordinals_table, qboolean directpath )
 {
-	return LoadLibraryA( dllname );
+	dll_user_t *hInst;
+
+	hInst = FS_FindLibrary( dllname, directpath );
+	if( !hInst ) return NULL; // nothing to load
+
+	return LoadLibraryA( hInst->fullPath );
 }
 
 void COM_FreeLibrary( void *hInstance )