Test Directory collisions may confuse users

[chick]

A nice feature of Testers2 is that it bases the name of the work directory for a test from the scalaTest test name. This can lead to potential collisions if two different tests share the same tests name.
Proposed fix, incorporate class name of test into the test directory
Example

class X extends FreeSpec with ChiselScalatestTester {
  "basic compile should work" in {}
}
class Y extends FreeSpec with ChiselScalatestTester {
  "basic compile should work" in {}
}

The working directory for both these tests will be the same, i.e. "test_run_dir/basic_compile_should_work".
It might not matter but it can create weird errors if the the two tests are similar and have different backends.

[ducky64]

That sounds reasonable. Not sure if there was a reason it's not currently being prefixed with the class name, but I don't think so?