Bundle multiple libc ERTS runtimes in a single binary

[bsedat]

After some ERTS libc architecture mixups (entirely my user error) I wanted to propose an enhancement to bundle multiple ERTS runtimes and at runtime decide which version to extract based on detecting the user's libc environment.

Another issue I ran into (not Burrito's fault either) but running the wrong ERTS gives an error message like:

/tmp/.tinfoil/XXXX_erts-12.1.5_XXXX/releases/XXXX/../../erts-12.1.5/bin/erl: 10: exec: /tmp/.tinfoil/XXXX_erts-12.1.5_XXXX/erts-12.1.5/bin/erlexec: not found

which is really complaining that erlexec could not find the libc .so file.