Compiled on RPI4B-4G with 5.10.77-piCore-v8

Compile Flags:
CFLAGS='-march=armv8-a+crc -mtune=cortex-a72 -Os -pipe -flto -fuse-linker-plugin -fno-exceptions'
CXXFLAGS='-march=armv8-a+crc -mtune=cortex-a72 -Os -pipe -flto -fuse-linker-plugin -fno-exceptions -fno-rtti'
LDFLAGS='-Wl,-O1'
export CFLAGS CXXFLAGS LDFLAGS

Dependencies:
compiletc
automake
libtool-dev
python3.8
llvm-bin

Commands:

wget https://gitlab.gnome.org/GNOME/libxml2/-/archive/v2.9.13/libxml2-v2.9.13.tar.gz

tar -xf libxml2-v2.9.13.tar.gz

cd libxml2-v2.9.13/

# fix LTO plugin
P=/usr/local/libexec/gcc/aarch64-unknown-linux-gnu/10.2.0/liblto_plugin.so.0.0.0
sudo mkdir -p /usr/local/lib/bfd-plugins
sudo ln -sfv $P /usr/local/lib/bfd-plugins/liblto_plugin.so

./autogen.sh --prefix=/usr/local --enable-shared --enable-static --with-python=/usr/local/bin/python3

time make -j4
real    2m 12.22s
user    3m 14.75s
sys     0m 13.99s

DESTDIR=/tmp/packing-libxml2 make install

llvm-strip --strip-debug /tmp/packing-libxml2/usr/local/lib/*.a
llvm-strip --strip-debug /tmp/packing-libxml2/usr/local/lib/python3.8/site-packages/*.a

# dev
mkdir -p /tmp/packing-libxml2-dev/usr/local/lib
mv /tmp/packing-libxml2/usr/local/include /tmp/packing-libxml2-dev/usr/local
mv /tmp/packing-libxml2/usr/local/lib/*a /tmp/packing-libxml2-dev/usr/local/lib
mv /tmp/packing-libxml2/usr/local/lib/pkgconfig/ /tmp/packing-libxml2-dev/usr/local/lib
mv /tmp/packing-libxml2/usr/local/lib/cmake /tmp/packing-libxml2-dev/usr/local/lib
mv /tmp/packing-libxml2/usr/local/lib/xml2Conf.sh /tmp/packing-libxml2-dev/usr/local/lib
mkdir -p /tmp/packing-libxml2-dev/usr/local/share
mv /tmp/packing-libxml2/usr/local/share/aclocal/ /tmp/packing-libxml2-dev/usr/local/share
mkdir -p /tmp/packing-libxml2-dev/usr/local/bin
mv /tmp/packing-libxml2/usr/local/bin/xml2-config /tmp/packing-libxml2-dev/usr/local/bin
mkdir -p /tmp/packing-libxml2-dev/usr/local/lib/python3.8/site-packages
mv /tmp/packing-libxml2/usr/local/lib/python3.8/site-packages/*a /tmp/packing-libxml2-dev/usr/local/lib/python3.8/site-packages

# python
mkdir -p /tmp/packing-libxml2-python/usr/local/lib/
mv /tmp/packing-libxml2/usr/local/lib/python3.8 /tmp/packing-libxml2-python/usr/local/lib/

# doc
mkdir -p /tmp/packing-libxml2-doc/usr/local/
mv /tmp/packing-libxml2/usr/local/share /tmp/packing-libxml2-doc/usr/local/

# bin
mkdir -p /tmp/packing-libxml2-bin/usr/local/
mv /tmp/packing-libxml2/usr/local/bin /tmp/packing-libxml2-bin/usr/local/

# strip
strip --strip-unneeded /tmp/packing-libxml2-bin/usr/local/bin/*
strip --strip-unneeded /tmp/packing-libxml2/usr/local/lib/libxml2.so.2.9.13
strip --strip-unneeded /tmp/packing-libxml2-python/usr/local/lib/python3.8/site-packages/*so

# squash
cd /tmp
sudo chown -R root:root packing-libxml2*
for D in packing-libxml2*; do mksquashfs $D ${D#packing-}.tcz -quiet; done