(Make) Build a single monolithic LLVMPolly.so

This reverts the broken modularized build.

This builds the classic loadable module. The separation
of library and plugin is yet to be done in a future patch.

git-svn-id: https://llvm.org/svn/llvm-project/polly/trunk@203952 91177308-0d34-0410-b5e6-96231b3b80d8