fix Examples/guile/multivalue & multimap regress tests

ld: error: unknown argument '-I/usr/local/include'
ld: error: unknown argument '-pthread'
ld: error: unknown argument '-pthread'
ld: error: unable to find library -lm

Index: configure
--- configure.orig
+++ configure
@@ -6648,7 +6648,7 @@ then
 	*-*-linux*) LDSHARED="\$(CC) -shared";;
 	*-*-dgux*) LDSHARED="ld -G";;
 	*-*-freebsd3*) LDSHARED="\$(CC) -shared";;
-	*-*-freebsd* | *-*-openbsd*) LDSHARED="ld -Bshareable";;
+	*-*-freebsd* | *-*-openbsd*) LDSHARED="cc -shared";;
 	*-*-netbsd*)
 		if [ "`\$(CC) -dM -E - </dev/null | grep __ELF__`" != "" ]
 		then