Gettext-0.21

Reference:8.31. Gettext-0.21. Fix the build system:

patch -Np1 -i gettext-0.21-bld-20220214.patch

Fix some sources:

patch -Np1 -i gettext-0.21-src-20220214.patch

./configure --prefix=/libs \
            --disable-rpath \
            --includedir=/libs/inc \
            --datarootdir=/libs/dat \
            --mandir=/libs/man \
            --docdir=/tmp \
            --infodir=/tmp

make
make install