JUnit XML has a hostname attribute as part of testsuite element. At least in a number of schemas I found.

Adding support for this attribute would allow us:

1. Possibly displaying it along with the testcase or testsuite results.
2. Would make deduplication easier for parallel jobs or same tests running on diff machines/architectures/operating systems.
3. Since a different slave could be used for a different test run would make it easier to see how results vary if we can tell which slave was used to run the tests.