As pointed out on a recent JIRA, crash traces don't mention what
version of Swift you were running. Usually that can be gleaned from
the path, but not always.
This may help us reproduce a failing build when all we have is a build
log, and will become much more important in batch mode when we
/really/ need to know what ended up in what batch.
For now, this doesn't include /output/ filelists, because David's
about to mess with that code anyway to make things better around
supplementary outputs in batch mode. There is one weirdness there,
though, which is that ArgsToFrontendInputsConverter peeks at the
outputs to see whether we're doing single-threaded or multi-threaded
WMO.
Revert "add a hackaround for rdar://15753317. I don't unerstand the code enough to tell if this is the right fix."
This reverts commit 416983b0734dde6979c98971948068c7a157e336.
Swift SVN r11942
