The hack (optimisation?) to normalise integer literals when below some
threshold is fine on the RHS, but on the LHS causes problems since we
need them in normal form for pattern matching. Fixes#112
We also need to separate building the runtests binary from running the
tests, because runtests refers to the boostrap libraries, and the tests
refer to the newly built libraries.
This worked locally, using inconsistent TTC versions for the bootstrap
version and new version, but let's see what it does on a clean machine
* Ignore build artifacts in 'tests' directory
* Remove unused variables in makefiles
* Add 'bootstrap-clean' rule to delete build artifacts from 'bootstrap' directory
* Add 'distclean' rule to delete all build artifacts from the source tree
