stop exposing hidden defines in public opensslconf.h

pull in hidden headers instead, patching drectly for Windows support

ssl/Makefile.am

@@ -31,6 +31,7 @@ remove_bs_objects: libssl.la
 	-$(AR) dv $(abs_top_builddir)/ssl/.libs/libssl.a \
 	    bs_ber.o bs_cbb.o bs_cbs.o
 
+libssl_la_CPPFLAGS = -I$(top_srcdir)/ssl/hidden ${AM_CPPFLAGS}
 libssl_la_LDFLAGS = -version-info @LIBSSL_VERSION@ -no-undefined -export-symbols $(top_srcdir)/ssl/ssl.sym
 libssl_la_LIBADD = $(abs_top_builddir)/crypto/libcrypto.la $(PLATFORM_LDADD)
 libssl_la_LIBADD += libbs.la