winecrt0: Add DllMainCRTStartup.

dlls/winecrt0/Makefile.in

 MODULE    = libwinecrt0.a
 
 C_SRCS = \
+	crt_dllmain.c \
 	debug.c \
 	delay_load.c \
 	dll_entry.c \

dlls/winecrt0/crt_dllmain.c

+/*
+ * DllMainCRTStartup default entry point
+ *
+ * Copyright 2019 Jacek Caban for CodeWeavers
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA
+ */
+
+#ifdef _WIN32
+
+#include <stdarg.h>
+#include <stdio.h>
+#include "windef.h"
+#include "winbase.h"
+
+BOOL WINAPI DllMainCRTStartup( HINSTANCE inst, DWORD reason, void *reserved )
+{
+    return DllMain( inst, reason, reserved );
+}
+
+#endif