Acts DPC++ Patch, master branch (2020.08.15.)
Introduced an Acts patch when using the very latest clang compiler. Which pretty much equates to using Intel's DPC++ compiler.
It's necessary because of yet another incompatibility between LLVM and GCC 8's libstdc++.
This MR is very much related to both !714 (merged) and athena!35624 (merged).
Pinging @pagessin. (Something like this will arrive together with @aczirkos's SYCL plugin into the main Acts repository in not too long as well.)