Create unit-test for Mul.sv eqy

[oharboe]

Description

An attempt at creating a test was started here, but a unit-test seems more approperiate.

A eqy unit-test can span synthesis and ORFS .tcl scripts, so it seems approperiate to have unit-tests with eqy in ORFS rather than in OpenROAD.

Tasks:

• [ ] How can Mul.sv in #2300 be best expressed as a fast eqy unit-test in ORFS and how are all steps covered? In particular it would be useful to have some unit-tests that start with checking synthesis.
• [ ] . env.sh and make DESIGN_CONFIG=designs/asap7/mul/config.mk in #2300 fails locally because eqy is not in the path, even though it is in dependencies/bin/eqy
• [ ] Hook up this test to CI
• [ ] Investigate the eqy failure that we're trying to study here, seems like this is a known problem in Yosys. https://github.com/YosysHQ/yosys/issues/3879 https://github.com/YosysHQ/yosys/pull/3882
• [ ] This is an attempt to rearticulate this test-case in ORFS speak: https://github.com/The-OpenROAD-Project/bazel-orfs/pull/119

Suggested Solution

Not sure about the best way to test this in ORFS.

Additional Context

No response

[oharboe]

@maliberty Per discussion, I think this is possibly a very obtuse one-off bug in Yosys, never seen anything like it, so it does not seem worth it to add a generic yosys eqy testing capability in ORFS.