Verification phase that checks if, for every write, at least one write barrier is present at all
paths leading to the previous safepoint. For every write, necessitating a write barrier, a
bottom-up traversal of the graph is performed up to the previous safepoints via all possible
paths. If, for a certain path, no write barrier satisfying the processed write is found, an
assertion is generated.
Fields inherited from class com.oracle.graal.phases.BasePhase