Add new tests to backends and architecture;
Merge commit "Add regression test for Yosys PR 896"

Testing problems:

1. coverage_html/passes/equiv/equiv_make.cc.gcov.html - 164-227 are not
covered;
2. coverage_html/passes/equiv/equiv_add.cc.gcov.html - is not covered
("ERROR: This command must be executed in module context!")