Fix PDB virtual functions recognition in analysis

[notxvilka]

Your checklist for this pull request

• I've read the guidelines for contributing to this repository.
• I made sure to follow the project's coding style.
• I've documented every RZ_API function and struct this PR changes.
• I've added tests that prove my changes are effective (required for changes to RZ_API).
• I've updated the Rizin book with the relevant information (if needed).
• I've used AI tools to generate fully or partially these code changes and I'm sure the changes are not copyrighted by somebody else.

Detailed description

Previously PDB analysis integration missed virtual functions, now it doesn't.

Note, the removal of const for the RzCore in the context is required because rz_core_analysis_fcn() doesn't have const RzCore in its signature, and many callers - it would cause many unrelated changes and better to handle separately.

Test plan

CI is green

Closing issues

Closes #955

[codecov]

Codecov Report

❌ Patch coverage is 82.60870% with 4 lines in your changes missing coverage. Please review.
✅ Project coverage is 49.28%. Comparing base (c9a372c) to head (5a0be00).

Files with missing lines	Patch %	Lines
librz/core/cpdb.c	80.95%	1 Missing and 3 partials ⚠️

Additional details and impacted files

Files with missing lines	Coverage Δ
librz/arch/fcn.c	71.65% <100.00%> (+0.03%)	⬆️
librz/core/cpdb.c	73.64% <80.95%> (+0.59%)	⬆️

... and 18 files with indirect coverage changes

---

Continue to review full report in Codecov by Harness.

Legend - Click here to learn more
Δ = absolute <relative> (impact), ø = not affected, ? = missing data
Powered by Codecov. Last update c9a372c...5a0be00. Read the comment docs.

🚀 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.