The loop makes the test runner noticably slower to run. That doesn't matter so much for CI, but is a little inconvenient for local testing.

The drop impl forMemoryMapBackingMemory is no longer conditional, so it's not particularly different from the many other types that internally allocate.

Checklist

• Sensible git history (for example, squash "typo" or "fix" commits). See theRewriting History guide for help.
• Update the changelog (if necessary)