Generic/ScopeIndent: don't flag comments between stacked case statements

[lazerg]

Description

Generic.WhiteSpace.ScopeIndent flagged the indentation of a comment placed between two stacked case/default labels that share a body. It expected the comment to line up with the case body instead of with the labels.

The sniff already drops the indent it checks once it reaches a fall-through case/default label, but a comment sitting right before such a label was still checked against the previous case's body indent. It now checks against the label indent, so a comment aligned with the labels no longer errors, and a comment at the body indent still passes too.

Suggested changelog entry

Fixed:

• Generic.WhiteSpace.ScopeIndent: a comment between stacked case/default statements is no longer flagged as incorrectly indented.

Related issues/external references

Fixes #1460

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)
  • This change is only breaking for integrators, not for external standards or end-users.
• Documentation improvement

PR checklist

• I have checked there is no other PR open for the same change.
• I have read the Contribution Guidelines.
• I grant the project the right to include and distribute the code under the BSD-3-Clause license (and I have the right to grant these rights).
• I have added tests to cover my changes.
• I have verified that the code complies with the projects coding standards.
• [Required for new sniffs] I have added XML documentation for the sniff.
• I have opened a sister-PR in the documentation repository to update the Wiki.