fix(cl): normalize C/C++ documentation comment markers

[Copilot]

Comment extraction could leak decorative asterisks from block-comment delimiters into generated Go docs, and retain the ! marker from /*! ... */ comments.

• Formatting: Strip bang-style markers and discard lines containing only delimiter asterisks.
• Coverage: Add regression cases for Python-style banner comments and standard C/C++ block and line comments.

/**********
Documentation text.
**********/

The generated Go doc comment contains only // Documentation text..

• Fixes fix(cl): comments format bugfix #930

[xushiwei]

@copilot The issue hasn't been resolved; CI on the Mac platform is still failing.

[Copilot]

@copilot The issue hasn't been resolved; CI on the Mac platform is still failing.

The macOS failure came from enabling -fparse-all-comments for every config, which changed LLVM goldens. It is now opt-in via KeepDoc and enabled for Python; the LLVM system and Python golden tests pass locally. Fixed in 01e886a.