Revert "[Coroutines] ABI Objects to improve code separation between different ABIs, users and utilities. (#109338)"
This reverts commit 2e414799d0ad511cd7999895014a2cae2ea5e3e3.
Reason: buildbot breakage
(https://lab.llvm.org/buildbot/#/builders/51/builds/4105)
(This was the only new CL.)
/home/b/sanitizer-aarch64-linux/build/llvm-project/llvm/lib/Transforms/Coroutines/ABI.h:71:31: error: 'llvm::coro::AsyncABI' has virtual functions but non-virtual destructor [-Werror,-Wnon-virtual-dtor]
71 | class LLVM_LIBRARY_VISIBILITY AsyncABI : public BaseABI {
etc.