build: Be cross-compilation-ready.

* Makefile.am (.scm.go): Pass `--target=$(host)'.

* configure.ac: Use `AC_CANONICAL_HOST'.

Makefile.am

@@ -50,6 +50,7 @@ CLEANFILES = $(GOBJECTS) *.log
 	GUILE_LOAD_COMPILED_PATH="$(top_builddir):$$GUILE_LOAD_COMPILED_PATH"	\
 	$(GUILD) compile -L "$(top_srcdir)"					\
 	  -Wformat -Wunbound-variable -Warity-mismatch				\
+	  --target="$(host)"							\
 	  -o "$@" "$<"
 
 SUFFIXES = .go

configure.ac

@@ -14,6 +14,8 @@ AC_CONFIG_MACRO_DIR([m4])
 guilemoduledir="${datarootdir}/guile/site/2.0"
 AC_SUBST([guilemoduledir])
 
+AC_CANONICAL_HOST
+
 PKG_CHECK_MODULES([GUILE], [guile-2.0])
 AC_PATH_PROG([GUILE], [guile])
 AC_PATH_PROG([GUILD], [guild])