tap: check if selected master cells are placeable

[eder-matheus]

Summary

TAP could use cells that are not placeable as tapcells or endcaps. This PR adds a check to prevent it, throwing an error message when it happens.

Type of Change

• Bug fix
• New feature

Impact

Prevent wrong cells to be used as tap/endcaps.

Verification

• I have verified that the local build succeeds (./etc/Build.sh).
• I have run the relevant tests and they pass.
• My code follows the repository's formatting guidelines.
• I have included tests to prevent regressions.
• I have signed my commits (DCO).

Related Issues

Fixes https://github.com/The-OpenROAD-Project-private/OpenROAD-flow-scripts/issues/1783.

[gemini-code-assist]

Code Review

This pull request introduces validation checks to ensure that the master cells provided for tapcells and endcaps are core auto-placeable. If a master cell is not placeable in core rows, an error is logged to prevent issues during detailed placement. Additionally, a new integration test invalid_master_class has been added to verify this behavior. There are no review comments, and I have no feedback to provide.

[eder-matheus]

@codex review

[chatgpt-codex-connector]

Codex Review: Didn't find any major issues. What shall we delve into next?

Reviewed commit: a514e1fa5d

ℹ️ About Codex in GitHub

Your team has set up Codex to review pull requests in this repo. Reviews are triggered when you

• Open a pull request for review
• Mark a draft as ready
• Comment "@codex review".

If Codex has suggestions, it will comment; otherwise it will react with 👍.

Codex can also answer questions or update the PR. Try commenting "@codex address that feedback".

[eder-matheus]

@gudeh @jeffng-or FYI