I get:
/bin/sh ../../libtool  --tag=CC   --mode=link x86_64-pc-linux-gnu-gcc -pthread -I/usr/include/gnome-desktop-3.0 -I/usr/include/gtk-3.0 -I/usr/include/at-spi2-atk/2.0 -I/usr/include/gtk-3.0 -I/usr/include/gio-unix-2.0/ -I/usr/include/cairo -I/usr/include/pango-1.0 -I/usr/include/harfbuzz -I/usr/include/pango-1.0 -I/usr/include/atk-1.0 -I/usr/include/cairo -I/usr/include/pixman-1 -I/usr/include/freetype2 -I/usr/include/libdrm -I/usr/include/polkit-1 -I/usr/include/gdk-pixbuf-2.0 -I/usr/include/libpng15 -I/usr/include/glib-2.0 -I/usr/lib64/glib-2.0/include -I/usr/include/gsettings-desktop-schemas  -march=native -pipe -O2 -ggdb  -Wl,-O1 -Wl,--as-needed -Wl,--hash-style=gnu -o test-timezone test_timezone-test-timezone.o test_timezone-cc-timezone-map.o test_timezone-tz.o -lgthread-2.0 -pthread -lrt -lgio-2.0 -lgnome-desktop-3 -lgtk-3 -lgdk-3 -lpangocairo-1.0 -lpango-1.0 -latk-1.0 -lcairo-gobject -lcairo -lpolkit-gobject-1 -lgio-2.0 -lgdk_pixbuf-2.0 -lgobject-2.0 -lglib-2.0  -lm 
CREATED org.gnome.controlcenter.datetime.policy
timedated.c: In function 'timedate1_proxy_get_type':
timedated.c:1252:39: error: expected expression before 'Timedate1Proxy'
timedated.c:1252:55: error: expected ';' before '{' token
timedated.c: In function 'timedate1_proxy_init':
timedated.c:1443:15: warning: assignment makes pointer from integer without a cast [enabled by default]
timedated.c: In function 'timedate1_skeleton_get_type':
timedated.c:1883:39: error: expected expression before 'Timedate1Skeleton'
timedated.c:1883:58: error: expected ';' before '{' token
timedated.c: In function 'timedate1_skeleton_init':
timedated.c:2044:18: warning: assignment makes pointer from integer without a cast [enabled by default]
make[5]: *** [timedated.lo] Error 1
make[5]: *** Waiting for unfinished jobs....
libtool: link: x86_64-pc-linux-gnu-gcc -pthread -I/usr/include/gnome-desktop-3.0 -I/usr/include/gtk-3.0 -I/usr/include/at-spi2-atk/2.0 -I/usr/include/gtk-3.0 -I/usr/include/gio-unix-2.0/ -I/usr/include/cairo -I/usr/include/pango-1.0 -I/usr/include/harfbuzz -I/usr/include/pango-1.0 -I/usr/include/atk-1.0 -I/usr/include/cairo -I/usr/include/pixman-1 -I/usr/include/freetype2 -I/usr/include/libdrm -I/usr/include/polkit-1 -I/usr/include/gdk-pixbuf-2.0 -I/usr/include/libpng15 -I/usr/include/glib-2.0 -I/usr/lib64/glib-2.0/include -I/usr/include/gsettings-desktop-schemas -march=native -pipe -O2 -ggdb -Wl,-O1 -Wl,--hash-style=gnu -o test-timezone-gfx test_timezone_gfx-test-timezone-gfx.o test_timezone_gfx-tz.o -pthread  -Wl,--as-needed -lgthread-2.0 -lrt -lgnome-desktop-3 -lgtk-3 -lgdk-3 -lpangocairo-1.0 -lpango-1.0 -latk-1.0 -lcairo-gobject -lcairo -lpolkit-gobject-1 -lgio-2.0 -lgdk_pixbuf-2.0 -lgobject-2.0 -lglib-2.0 -lm -pthread
libtool: link: x86_64-pc-linux-gnu-gcc -pthread -I/usr/include/gnome-desktop-3.0 -I/usr/include/gtk-3.0 -I/usr/include/at-spi2-atk/2.0 -I/usr/include/gtk-3.0 -I/usr/include/gio-unix-2.0/ -I/usr/include/cairo -I/usr/include/pango-1.0 -I/usr/include/harfbuzz -I/usr/include/pango-1.0 -I/usr/include/atk-1.0 -I/usr/include/cairo -I/usr/include/pixman-1 -I/usr/include/freetype2 -I/usr/include/libdrm -I/usr/include/polkit-1 -I/usr/include/gdk-pixbuf-2.0 -I/usr/include/libpng15 -I/usr/include/glib-2.0 -I/usr/lib64/glib-2.0/include -I/usr/include/gsettings-desktop-schemas -march=native -pipe -O2 -ggdb -Wl,-O1 -Wl,--hash-style=gnu -o test-endianess test_endianess-test-endianess.o test_endianess-date-endian.o -pthread  -Wl,--as-needed -lgthread-2.0 -lrt -lgnome-desktop-3 -lgtk-3 -lgdk-3 -lpangocairo-1.0 -lpango-1.0 -latk-1.0 -lcairo-gobject -lcairo -lpolkit-gobject-1 -lgio-2.0 -lgdk_pixbuf-2.0 -lgobject-2.0 -lglib-2.0 -lm -pthread
libtool: link: x86_64-pc-linux-gnu-gcc -pthread -I/usr/include/gnome-desktop-3.0 -I/usr/include/gtk-3.0 -I/usr/include/at-spi2-atk/2.0 -I/usr/include/gtk-3.0 -I/usr/include/gio-unix-2.0/ -I/usr/include/cairo -I/usr/include/pango-1.0 -I/usr/include/harfbuzz -I/usr/include/pango-1.0 -I/usr/include/atk-1.0 -I/usr/include/cairo -I/usr/include/pixman-1 -I/usr/include/freetype2 -I/usr/include/libdrm -I/usr/include/polkit-1 -I/usr/include/gdk-pixbuf-2.0 -I/usr/include/libpng15 -I/usr/include/glib-2.0 -I/usr/lib64/glib-2.0/include -I/usr/include/gsettings-desktop-schemas -march=native -pipe -O2 -ggdb -Wl,-O1 -Wl,--hash-style=gnu -o test-timezone test_timezone-test-timezone.o test_timezone-cc-timezone-map.o test_timezone-tz.o -pthread  -Wl,--as-needed -lgthread-2.0 -lrt -lgnome-desktop-3 -lgtk-3 -lgdk-3 -lpangocairo-1.0 -lpango-1.0 -latk-1.0 -lcairo-gobject -lcairo -lpolkit-gobject-1 -lgio-2.0 -lgdk_pixbuf-2.0 -lgobject-2.0 -lglib-2.0 -lm -pthread
make[5]: Leaving directory `/var/tmp/portage/gnome-base/gnome-control-center-3.8.4/work/gnome-control-center-3.8.4/panels/datetime'
make[4]: *** [all-recursive] Error 1
make[4]: Leaving directory `/var/tmp/portage/gnome-base/gnome-control-center-3.8.4/work/gnome-control-center-3.8.4/panels/datetime'
make[3]: *** [all] Error 2
make[3]: Leaving directory `/var/tmp/portage/gnome-base/gnome-control-center-3.8.4/work/gnome-control-center-3.8.4/panels/datetime'
make[2]: *** [all-recursive] Error 1
make[2]: Leaving directory `/var/tmp/portage/gnome-base/gnome-control-center-3.8.4/work/gnome-control-center-3.8.4/panels'
make[1]: *** [all-recursive] Error 1
make[1]: Leaving directory `/var/tmp/portage/gnome-base/gnome-control-center-3.8.4/work/gnome-control-center-3.8.4'
make: *** [all] Error 2