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

Reference:
https://linux.die.net/man/1/gcc
If you use multiple -O options, with or without level numbers, the last such option is the one that is effective.
By exporting flags, -Os goes after -O3

Compile Flags:
# ../deps/v8/src/torque/implementation-visitor.cc:3375:36: error: exception handling disabled, use '-fexceptions' to enable
CFLAGS='-march=armv8-a+crc -mtune=cortex-a72 -Os -pipe'
CXXFLAGS='-march=armv8-a+crc -mtune=cortex-a72 -Os -pipe'
LDFLAGS='-Wl,-O1'
export CFLAGS CXXFLAGS LDFLAGS

Dependencies:
compiletc
python3.8
c-ares-dev
icu-dev
libuv-dev
nghttp2-dev
openssl-dev
llvm-bin

Commands:

# 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

# extract in /tmp (pi4 has enough memory)
tar -xf node-v16.14.0.tar.gz

cd node-v16.14.0/

patch -Np1 < Favor4Size.patch

./configure --prefix=/usr/local --shared-cares --shared-libuv --shared-openssl --shared-nghttp2 --shared-zlib --with-intl=system-icu --enable-lto --verbose

# compile and install in a go
nohup time make -j4 install DESTDIR=/tmp/packing-node &> /tmp/node-build-install.log &
real    4h 37m 21s
user    17h 18m 25s
sys     44m 39.36s

cd /tmp/packing-node

# find . -type f -exec file {} ';' > /tmp/file.info
# grep ELF /tmp/file.info

strip --strip-unneeded ./usr/local/bin/node

# dev
mkdir -p /tmp/packing-node-dev/usr/local/
mv /tmp/packing-node/usr/local/include /tmp/packing-node-dev/usr/local/