PAPI Profiling support.

This adds support for PAPI based SCoP profiling. Using it still
requires a runtime library.
Accumulate all valid regions
PapiProf: clang-format & clang-modernize
polli: Disable Execution support
PapiProf: Don't forget to initialize the passes
polli: Preliminary library linking support

This adds basic support for linking to other (shared)
libraries for JIT'ted programs.