Move gettext-tools/lib/xmalloc.c to gnulib-local/lib/xmalloc.c.

diff --git a/gettext-tools/lib/xmalloc.c b/gnulib-local/lib/xmalloc.c
similarity index 100%
rename from gettext-tools/lib/xmalloc.c
rename to gnulib-local/lib/xmalloc.c