eqy: Add eqy_test rule for equivalence checking and test

[oharboe]

@hovind FYI

$ bazel run Mul_synth_eqy
INFO: Analyzed target //:Mul_synth_eqy (0 packages loaded, 0 targets configured).
INFO: Found 1 target...
Target //:Mul_synth_eqy up-to-date:
  bazel-bin/Mul_synth_eqy.run.sh
INFO: Elapsed time: 0.213s, Critical Path: 0.00s
INFO: 1 process: 1 internal.
INFO: Build completed successfully, 1 total action
INFO: Running command line: external/bazel_tools/tools/test/test-setup.sh ./Mul_synth_eqy.run.sh
exec ${PAGER:-/usr/bin/less} "$0" || exit 1
Executing tests from //:Mul_synth_eqy
-----------------------------------------------------------------------------
EQY 15:47:26 [Mul_synth_eqy] read_gold: starting process "yosys -ql Mul_synth_eqy/gold.log Mul_synth_eqy/gold.ys"
EQY 15:47:26 [Mul_synth_eqy] read_gold: finished (returncode=0)
EQY 15:47:26 [Mul_synth_eqy] read_gate: starting process "yosys -ql Mul_synth_eqy/gate.log Mul_synth_eqy/gate.ys"
EQY 15:47:26 [Mul_synth_eqy] read_gate: finished (returncode=0)
EQY 15:47:26 [Mul_synth_eqy] combine: starting process "yosys -ql Mul_synth_eqy/combine.log Mul_synth_eqy/combine.ys"
EQY 15:47:26 [Mul_synth_eqy] combine: finished (returncode=0)
EQY 15:47:26 [Mul_synth_eqy] partition: starting process "cd Mul_synth_eqy; yosys -ql partition.log partition.ys"
EQY 15:47:26 [Mul_synth_eqy] partition: finished (returncode=0)
EQY 15:47:26 [Mul_synth_eqy] run: starting process "make -C Mul_synth_eqy -f strategies.mk"
EQY 15:47:26 [Mul_synth_eqy] run: make: Entering directory '/home/oyvind/.cache/bazel/_bazel_oyvind/6e078b44989a9ce1500a63165a20fd2a/execroot/_main/bazel-out/k8-fastbuild/bin/Mul_synth_eqy.run.sh.runfiles/_main/Mul_synth_eqy'
EQY 15:47:26 [Mul_synth_eqy] run: Running strategy 'sby' on 'Mul.io_dst'..
EQY 15:47:26 [Mul_synth_eqy] run: Could not prove equivalence of partition 'Mul.io_dst' using strategy 'sby': partitions not equivalent
EQY 15:47:26 [Mul_synth_eqy] run: make -f strategies.mk summary
EQY 15:47:26 [Mul_synth_eqy] run: make[1]: Entering directory '/home/oyvind/.cache/bazel/_bazel_oyvind/6e078b44989a9ce1500a63165a20fd2a/execroot/_main/bazel-out/k8-fastbuild/bin/Mul_synth_eqy.run.sh.runfiles/_main/Mul_synth_eqy'
EQY 15:47:26 [Mul_synth_eqy] run: make[1]: Leaving directory '/home/oyvind/.cache/bazel/_bazel_oyvind/6e078b44989a9ce1500a63165a20fd2a/execroot/_main/bazel-out/k8-fastbuild/bin/Mul_synth_eqy.run.sh.runfiles/_main/Mul_synth_eqy'
EQY 15:47:26 [Mul_synth_eqy] run: make: Leaving directory '/home/oyvind/.cache/bazel/_bazel_oyvind/6e078b44989a9ce1500a63165a20fd2a/execroot/_main/bazel-out/k8-fastbuild/bin/Mul_synth_eqy.run.sh.runfiles/_main/Mul_synth_eqy'
EQY 15:47:26 [Mul_synth_eqy] run: finished (returncode=0)
EQY 15:47:26 [Mul_synth_eqy] Warning: Failed to prove equivalence for 1/1 partitions:
EQY 15:47:26 [Mul_synth_eqy] Failed to prove equivalence of partition Mul.io_dst
EQY 15:47:26 [Mul_synth_eqy] summary: Elapsed clock time [H:MM:SS (secs)]: 0:00:00 (0)
EQY 15:47:26 [Mul_synth_eqy] summary: Elapsed process time [H:MM:SS (secs)]: 0:00:00 (0)
EQY 15:47:26 [Mul_synth_eqy] DONE (FAIL, rc=2)

[oharboe]

To examine failure:

bazel run Mul_synth_eqy -- --force -d /tmp/trash/

examine failure:

surfer /tmp/trash/strategies/Mul.io_dst/sby/Mul.io_dst/engine_0/trace.vcd