Improved glibc for x86-64 multililib and pure64 support

Note:
From now on we do not rely on the glibc32 package anymore by using a second
buildloop while building a 64bit multilib target.

architecture/x86-64/pkg_glibc_post.conf

@@ -0,0 +1,37 @@
+pkg_glibc32_preconf(){
+	if [ $buildloop -eq 2 ]; then
+		echo_status "Building 32 Bit Libraries."
+		# we need -m32 ... - still needed?
+		var_insert GCC_WRAPPER_INSERT " " "-m32"
+
+		arch_target="`echo $arch_target | arch2arch32`"
+		echo_status "Set arch_target to $arch_target ..."
+		set_confopt
+		# do not build the programs
+		hook_add premake 5 "cat > configparms <<-EOT
+build-programs=no
+EOT
+"
+
+		libdir=${libdir%64}32
+		slibdir=lib32
+
+		var_remove makeinstopt ' ' 'install'
+		var_append makeinstopt ' ' 'install-lib-all'
+
+		# glibc installs some headers it should not
+		var_append INSTALL_WRAPPER_FILTER "|" "sed -e 's,.*usr/include/.*\.h,/tmp/weg.h,'"
+	fi
+}
+
+if [ "$SDECFG_MULTILIB" != 1 ]; then
+	var_append patchfiles ' ' "$confdir/$pkg-$ver*pure64*.diff"
+else
+	var_append patchfiles ' ' "$confdir/$pkg-$ver*multilib*.diff"
+
+	if ! atstage toolchain; then
+		buildloops=2
+	fi
+
+	hook_add preconf 9 "pkg_glibc32_preconf"
+fi