gcc-multilib: install some multilib headers required for g++ -m32.

srcpkgs/gcc-multilib/libstdc++32-devel.template

@@ -0,0 +1,16 @@
+# Template file for 'libstdc++32-devel'.
+#
+short_desc="GCC Standard C++ Library (32bit) development files"
+long_desc="${long_desc}
+
+ This package contains a rewritten 32bit standard compliant GCC Standard
+ C++ development files and headers for x86_64 systems."
+
+Add_dependency run libstdc++-devel
+Add_dependency run libstdc++32
+
+do_install()
+{
+	mkdir -p ${DESTDIR}/usr
+	mv ${SRCPKGDESTDIR}/usr/include ${DESTDIR}/usr
+}