Deprecate make_and in favour of conjunction(expr, expr)

[tautschnig]

make_and does not necessarily produce an and_exprt, so its name is misleading. We already have conjunction(exprt::operandst), and will now have a variant thereof that takes exactly two operands.

• 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.
• n/a 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).
• n/a My commit message includes data points confirming performance improvements (if claimed).
• My PR is restricted to a single feature or bugfix.
• n/a White-space or formatting changes outside the feature-related changed lines are in commits of their own.

[kroening]

conjunction(a, b) behaves differently from conjunction({a, b}), which is confusing.
How about adding simplified_conjunction(a, b)?

[kroening]

Related to this, I have been considering to allow and_exprt{} (to mean true) and or_exprt{} (to mean false). Any opinions?

[tautschnig]

conjunction(a, b) behaves differently from conjunction({a, b}), which is confusing. How about adding simplified_conjunction(a, b)?

Addressed by invoking conjunction(a, b) when calling conjunction on a 2-element collection of operands.

[tautschnig]

Related to this, I have been considering to allow and_exprt{} (to mean true) and or_exprt{} (to mean false). Any opinions?

Wouldn't that create the weird case that a constructor creates an object of a different type?

[codecov]

Codecov Report

Attention: Patch coverage is 90.00000% with 2 lines in your changes missing coverage. Please review.

Project coverage is 80.38%. Comparing base (5cd085b) to head (18761f9).
Report is 2 commits behind head on develop.

Files with missing lines	Patch %	Lines
src/util/expr_util.cpp	0.00%	1 Missing ⚠️
src/util/std_expr.cpp	93.75%	1 Missing ⚠️

Additional details and impacted files

@@             Coverage Diff             @@
##           develop    #8450      +/-   ##
===========================================
- Coverage    80.38%   80.38%   -0.01%     
===========================================
  Files         1688     1688              
  Lines       207183   207188       +5     
  Branches        73       73              
===========================================
+ Hits        166549   166550       +1     
- Misses       40634    40638       +4     

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.

🚀 New features to boost your workflow:

• ❄️ Test Analytics: Detect flaky tests, report on failures, and find test suite problems.
• 📦 JS Bundle Analysis: Save yourself from yourself by tracking and limiting bundle sizes in JS merges.