[DO NOT REVIEW] asap7/mul: equivalence check

[oharboe]

@maliberty Several things needs doing here:

• . env.sh and make DESIGN_CONFIG=designs/asap7/mul/config.mk fails locally because eqy is not in the path, even though it is in dependencies/bin/eqy
• Hook up this test to Jenkins: looks like how this is done has changed or at least I didn't find where in ORFS to do this
• Investigate the eqy failure that we're trying to study here, seems like this is a known problem in Yosys. LEC failed after yosys synthesis YosysHQ/yosys#3879 extract_fa: Fix handling inversion of an FA xor output YosysHQ/yosys#3882
• This is an attempt to rearticulate this test-case in ORFS speak: eqy: Add eqy_test rule for equivalence checking and test bazel-orfs#119