Treat a non-atomic volatile load and store as a relaxed atomic at
system scope for the address spaces accessed. This will ensure all
relevant caches will be bypassed.
A volatile atomic is not changed and still only bypasses caches upto
the level specified by the SyncScope operand.
Differential Revision: https://reviews.llvm.org/D94214
We have a single noret intrinsic an a lot of special handling
around it. Declare it just as any other but do not define rtn
instructions itself instead.
Differential Revision: https://reviews.llvm.org/D87719
Tony