Avoid invalid shift caused by excessive object bits

[tautschnig]

Use mp_integer to compute the number of permitted objects as the number of object bits is related to the analysis target platform and need not be within the analysis-execution platform's limits.

• 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.

[Copilot]

Pull request overview

Updates pointer/object-bound computations to avoid undefined/invalid shifts when object_bits exceeds the host platform’s bit-width, by switching to mp_integer arithmetic.

Changes:

• Replace std::size_t(1) << object_bits with mp_integer-based power(2, object_bits) for computing max object count.
• Tighten object-limit checks (notably a >= max_objects).
• Replace an INVARIANT with a thrown analysis_exceptiont when pointer width is too small for object/offset encoding.

Reviewed changes

Copilot reviewed 2 out of 2 changed files in this pull request and generated 4 comments.

File	Description
src/solvers/smt2_incremental/convert_expr_to_smt.cpp	Uses mp_integer to compute max objects safely and throws an exception rather than asserting for width mismatch.
src/cprover/bv_pointers_wide.cpp	Uses mp_integer max objects and fixes boundary check to >= to prevent out-of-range object IDs.

---

💡 Add Copilot custom instructions for smarter, more guided reviews. Learn how to get started.

[codecov]

Codecov Report

❌ Patch coverage is 90.00000% with 1 line in your changes missing coverage. Please review.
✅ Project coverage is 80.01%. Comparing base (7a4df92) to head (1b8144b).

Files with missing lines	Patch %	Lines
src/cprover/bv_pointers_wide.cpp	66.66%	1 Missing ⚠️

Additional details and impacted files

@@             Coverage Diff             @@
##           develop    #8864      +/-   ##
===========================================
- Coverage    80.01%   80.01%   -0.01%     
===========================================
  Files         1703     1703              
  Lines       188396   188400       +4     
  Branches        73       73              
===========================================
+ Hits        150738   150739       +1     
- Misses       37658    37661       +3     

☔ 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.