This lets you have multiple #testcases declarations and they're taken
to be different dimensions of the test, so their cross product becomes
the total set of test cases. For example:
#testcases obsstore-on obsstore-off #testcases manifest-flat manifest-tree $ hg rebase ... ... #if obsstore-on $ hg log ... #endif
Note that this is an excellent way to slow down the test suite, so use
it with care.
The feature is implemented by replacing most of the "case" variables
that were strings before by an array of strings with each item a
different dimension of the test case. The file names are created by
joining the dimensions by "#"