build: fix libtool's refusal to link static libs into a dll

configure.ac

@@ -11,8 +11,21 @@ AC_CONFIG_SRCDIR([src/main.cpp])
 AC_CONFIG_HEADERS([src/config/bitcoin-config.h])
 AC_CONFIG_AUX_DIR([build-aux])
 AC_CONFIG_MACRO_DIR([build-aux/m4])
-LT_INIT([disable-shared])
+
 AC_CANONICAL_HOST
+
+dnl By default, libtool for mingw refuses to link static libs into a dll for
+dnl fear of mixing pic/non-pic objects, and import/export complications. Since
+dnl we have those under control, re-enable that functionality.
+
+case $host in
+  *mingw*)
+     lt_cv_deplibs_check_method="pass_all"
+  ;;
+esac
+
+LT_INIT([disable-shared])
+
 AH_TOP([#ifndef BITCOIN_CONFIG_H])
 AH_TOP([#define BITCOIN_CONFIG_H])
 AH_BOTTOM([#endif //BITCOIN_CONFIG_H])