#3284 Regression tests should check for simulator binaries first

[Philipp Klaus Krause]

After a recent svn update, I was wondering why all my regression testing was failing with timeouts. Despite the test binaries being identical to those of an older version that worked fine.
Turns out I forgot to do the ./configure to account for the uCsim rename.

Still, "make test-ucz80", etc should give a more meaningful error in this case.