win32: fix libtool: link: warning: undefined symbols not allowed in i…

…686-pc-mingw32 shared libraries

libtool: link: warning: undefined symbols not allowed in i686-pc-mingw32 shared libraries
libtool: link: ar cru .libs/libresourceplugin.a  .libs/resourceplugin.o .libs/plugin_resources.o
libtool: link: ranlib .libs/libresourceplugin.a
libtool: link: ( cd ".libs" && rm -f "libresourceplugin.la" && cp -p "../libresourceplugin.la" "libresourceplugin.la" )

gio/tests/Makefile.am

@@ -434,6 +434,10 @@ test.gresource: test.gresource.xml Makefile $(shell $(glib_compile_resources) --
 
 noinst_LTLIBRARIES = libresourceplugin.la
 
+if PLATFORM_WIN32
+no_undefined = -no-undefined
+endif
+
 libresourceplugin_la_SOURCES = resourceplugin.c plugin_resources.c
 libresourceplugin_la_LDFLAGS = -avoid-version -module $(no_undefined) -rpath $(libdir)
 libresourceplugin_la_LIBADD = $(LDADD)