[PATCH] New SystemZ backend: LLVM code changes

[Richard Sandiford]

  Well, I'd tried to split the tests so that each one tested a particular feature (described at the head of each file).  Most of them contain several subfunctions, it's not one-function-per-file or anything crazy like that :-)

  Sorry for the huge diff btw.  I should have stuck with what Uli did, and omit the tests.

http://llvm-reviews.chandlerc.com/D669