Remove Throwing-NULL check from goto_check_ct

[tautschnig]

This check was introduced in d2713b2, with no particular reason that
it should be enabled unconditionally. The test included in that commit
has --pointer-check set, suggesting that this always was the desired
behaviour. It was, however, only intended for the Java front-end: for
the C language, "throw" is not relevant, and C++ permits throwing NULL.
Therefore, remove this check from goto_check_ct.

• Each commit message has a non-empty body, explaining why the change was made.
• n/a 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.

[peterschrammel]

Shouldn't that go into java_bytecode/goto_check_java then?

[tautschnig]

Sort of, except goto_check_java should actually just be removed. See #6687 (and then #6686).

[tautschnig]

And then also goto_check_java actually has this code. I previously made it conditional on --pointer-check in there, just to realise that it actually is dead code.

[codecov]

Codecov Report

Merging #6685 (fe903fd) into develop (222d266) will increase coverage by 0.00%.
The diff coverage is 97.05%.

@@           Coverage Diff            @@
##           develop    #6685   +/-   ##
========================================
  Coverage    76.82%   76.82%           
========================================
  Files         1582     1582           
  Lines       182767   182758    -9     
========================================
  Hits        140403   140403           
+ Misses       42364    42355    -9     

Impacted Files	Coverage Δ
src/analyses/goto_check_c.cpp	91.60% <ø> (+0.79%)	⬆️
src/goto-programs/string_abstraction.h	100.00% <ø> (ø)
unit/util/piped_process.cpp	31.29% <33.33%> (ø)
src/ansi-c/c_typecheck_expr.cpp	76.45% <50.00%> (ø)
src/goto-programs/string_abstraction.cpp	92.46% <90.90%> (ø)
...solvers/smt2_incremental/smt_bit_vector_theory.cpp	100.00% <100.00%> (ø)
...rc/solvers/smt2_incremental/smt_solver_process.cpp	68.57% <100.00%> (ø)
src/util/piped_process.cpp	81.92% <100.00%> (ø)
...solvers/smt2_incremental/smt_bit_vector_theory.cpp	100.00% <100.00%> (ø)
... and 6 more

---

Continue to review full report at Codecov.

Legend - Click here to learn more
Δ = absolute <relative> (impact), ø = not affected, ? = missing data
Powered by Codecov. Last update 79c1637...fe903fd. Read the comment docs.