[PATCH 3 of 3 V3] run-tests: support multiple cases in .t test

[Jun Wu]

Excerpts from Yuya Nishihara's message of 2017-05-18 22:04:09 +0900:
> It appears we have (name, bname) pair, which is (str, bytes) respectively.
> Maybe one of them could be a @property.

"b" seems to be "basename", not "bytes". So they are different. "name" is
human-facing, like "testname (case XXX)", while "bname" is the filename.