Auto merge of #115586 - Zalathar:query, r=cjgillot

coverage: Simplify the `coverageinfo` query

The `coverageinfo` query walks through a `mir::Body`'s statements to find the total number of coverage counter IDs and coverage expression IDs that have been used, as this information is needed by coverage codegen.

This PR makes 3 nice simplifications to that query:
- Extract a common iterator over coverage statements, shared by both coverage-related queries
- Simplify the query's visitor from two passes to just one pass
- Explicitly track the highest seen IDs in the visitor, and only convert to a count right at the end

I also updated some related comments. Some had been invalidated by these changes, while others had already been invalidated by previous coverage changes.

0 files changed, 0 insertions, 0 deletions