[mlir][bufferization] Relax happens-before analysis (#223777)
On unstructured control-flow, the one-shot analysis is rather
conservative in regards to computing RaW conflicts, requiring strict
dominance which may not always be satisfied.
Relax this requirement to allow more cases to not be marked as
conflicting. Notably, readers/writers within a region that contains a
"diamond" or multiple loops are now handled.
This is a simpler version of
https://github.com/llvm/llvm-project/pull/223006 without the CFGLoopInfo
analysis, meaning it is a bit more conservative when analyzing regions
with nested loops.
llvm-project
606e2acd - [mlir][bufferization] Relax happens-before analysis (#223777)
