Revert "[OpenACC] Sema changes for +*&|^ reduction combiner recipes (… (#162920)
…#162740)"
This reverts commit 6010df0402e2f5cca0ded446a70492dedc43ab7e.
This apparently fails some sanitizer test as reported here:
https://github.com/llvm/llvm-project/pull/162740
It isn't really clear where this happens, but reverting as it is a
friday, and I have no idea if I'll be able to repro this anytime soon,
let alone fix it.