Merging all remainging files (headers, BuildDFG), added no-OpenCL hpvm-rt, removed unneeded patches, and added EPOCHS backend pass

Fixed 2 bugs exposed when adding new DNN

See merge request llvm/hpvm!37

When the GCC used to compile tensor runtime is not the system's default,
path to that GCC's GLIBC leaks into hpvm-clang
that can override system's default and cause GLIBC failure.