Fix spurious test failures especially for parallel builds via B2 with multiple variants.
This is caused by access to files with fixed names, so different variants of the same test or even different tests using the same filename may interfere with each other.
Also fix a "constant condition" warning in utf_name() and a bit of refactoring to make the tests easier to read (almost only renaming with no actual change to behavior)
Fix spurious test failures especially for parallel builds via B2 with multiple variants.
This is caused by access to files with fixed names, so different variants of the same test or even different tests using the same filename may interfere with each other.
Also fix a "constant condition" warning in
utf_name()
and a bit of refactoring to make the tests easier to read (almost only renaming with no actual change to behavior)