Regression tests/CMake: make SMT test labels unique

[thomasspriggs]

This fix is cherry-picked from ecd9870
I have raised this as a separate PR, as I would like to get this merged asap and to get it merged regardless of the discussions about the architectural merits of the original PR.

We already have cbmc-new-smt-backend in regression/cbmc. Having duplicate labels confuses ctest for it won't able able to uniquely identify test sets.

• Each commit message has a non-empty body, explaining why the change was made.
• Methods or procedures I have added are documented, following the guidelines provided in CODING_STANDARD.md.
• The feature or user visible behaviour I have added or modified has been documented in the User Guide in doc/cprover-manual/
• Regression or unit tests are included, or existing tests cover the modified code (in this case I have detailed which ones those are in the commit message).
• My commit message includes data points confirming performance improvements (if claimed).
• My PR is restricted to a single feature or bugfix.
• White-space or formatting changes outside the feature-related changed lines are in commits of their own.

[thomasspriggs]

@tautschnig I assume you have no objections to us merging this separately?

[codecov]

Codecov Report

Base: 78.39% // Head: 78.40% // Increases project coverage by +0.01% 🎉

Coverage data is based on head (ecd9870) compared to base (b03d870).
Patch has no changes to coverable lines.

Additional details and impacted files

@@             Coverage Diff             @@
##           develop    #7433      +/-   ##
===========================================
+ Coverage    78.39%   78.40%   +0.01%     
===========================================
  Files         1655     1659       +4     
  Lines       190281   190383     +102     
===========================================
+ Hits        149172   149276     +104     
+ Misses       41109    41107       -2     

Impacted Files	Coverage Δ
...o-instrument/contracts/dynamic-frames/dfcc_utils.h	0.00% <0.00%> (-100.00%)	⬇️
...ent/contracts/dynamic-frames/dfcc_spec_functions.h	0.00% <0.00%> (-100.00%)	⬇️
...t/contracts/dynamic-frames/dfcc_contract_handler.h	0.00% <0.00%> (-100.00%)	⬇️
...racts/dynamic-frames/dfcc_lift_memory_predicates.h	0.00% <0.00%> (-100.00%)	⬇️
...contracts/dynamic-frames/dfcc_contract_handler.cpp	71.64% <0.00%> (-28.36%)	⬇️
...ment/contracts/dynamic-frames/dfcc_swap_and_wrap.h	83.33% <0.00%> (-16.67%)	⬇️
src/goto-programs/goto_program.cpp	80.24% <0.00%> (-1.56%)	⬇️
...strument/contracts/dynamic-frames/dfcc_library.cpp	95.04% <0.00%> (-0.50%)	⬇️
src/ansi-c/c_typecheck_base.cpp	83.10% <0.00%> (-0.20%)	⬇️
.../goto-instrument/goto_instrument_parse_options.cpp	71.31% <0.00%> (-0.17%)	⬇️
... and 31 more

Help us with your feedback. Take ten seconds to tell us how you rate us. Have a feature suggestion? Share it here.

☔ View full report at Codecov.
📢 Do you have feedback about the report comment? Let us know in this issue.