make all test CC=fatcosmocc AR='fatcosmoar rcu'
This change introduces a program named mktemper.com which provides more
reliable and secure temporary file name generation for scripts. It also
makes our ar.com program more permissive in what commands it'll accept.
The cosmocc command is improved by this change too.
This new script is an alternative to the `cosmocc` command. It's still a
work in progress. It abstracts all the gory details of building separate
copies of your executable and then running the apelink.com program.