Update matmul example to the latest polly version

As the namings of the scops have changed, polly was not able to read in the user
given .jscop files. By renaming the provided files, polly now finds them again
and can use them to optimize the matmul function. We also update the generated
files to reflect the very latest version of Polly.

Merged from: https://llvm.org/svn/llvm-project/polly/trunk@182265

llvm-svn: 183376