[Refactor] Create nicer test cases from C/C++

Insert a header into the new testcase containing a sample RUN line a FIXME and
an XFAIL. Then insert the formated C code and finally the LLVM-IR without
attributes, the module ID or the target triple.


git-svn-id: https://llvm.org/svn/llvm-project/polly/trunk@211612 91177308-0d34-0410-b5e6-96231b3b80d8