Cross compile

TODO get working.

Official docs: https://gcc.gnu.org/install/build.html "Building a cross compiler" section.

Official wiki: https://gcc.gnu.org/wiki/Building_Cross_Toolchains_with_gcc

3 parameters identify the cross compiler: http://wiki.osdev.org/Target_Triplet

TODO: list all possible targets:

Name convention

Some samples:

Ubuntu 16.04:

arm-linux-gnueabi-: Ubuntu 16.04 binutils-arm-linux-gnueabi, binutils-arm-linux-gnueabihf packages
arm-linux-gnueabihf-: Ubuntu 16.04 gcc-arm-linux-gnueabihf
arm-linux-androidabi-: Android NDK 16
arm-none-eabi-: Ubuntu 16.04 gcc-arm-none-eabi package. Suitable to compile bare metal code that does not link to libc.
x86_64-linux-gnu-: Ubuntu 16.04 gcc package