[OpClassifier](fix) share cube upstream skip rules across both BFS paths

[245516766]

propagateCubeUpstreamForOp (triggered by handleFillInScfIf) re-coloured ExtractedLoadStore-related ops and ops inside a nested linalg region as CUBE because the three skip predicates (arith on tensors, isExtractedLoadStoreRelated, inside nested linalg region) only lived inline inside propagateCubeUpstream.

Extract the predicates into OpClassifierPass::shouldSkipCubeUpstream and call it from both BFS paths so they stay consistent.

New contributor declaration

• I am not making a trivial change, such as fixing a typo in a comment.

• I have written a PR description following these
  rules.

• I have run pre-commit run --from-ref origin/main --to-ref HEAD.

• Select one of the following.

  • I have added tests.
    • /test for lit tests
    • /unittest for C++ tests
    • /python/test for end-to-end tests
  • This PR does not need a test because FILL THIS IN.

• Select one of the following.

  • I have not added any lit tests.
  • The lit tests I have added follow these best practices,
    including the "tests should be minimal" section. (Usually running Python code
    and using the instructions it generates is not minimal.)

[github-actions]

🔍 OpenCodeReview found 1 issue(s) in this PR.

• ✅ Successfully posted inline: 1 comment(s)

[github-actions]

[maintainability · low]
Missing null check for op parameter. The function immediately dereferences op via op->getDialect() without checking for null. While all current callers (propagateCubeUpstream and propagateCubeUpstreamForOp) guarantee non-null before calling this function, adding a defensive null check at the top would make the function more robust against future misuse and consistent with isExtractedLoadStoreRelated (which has if (!op) return false;) and isInsideNestedLinalgRegion (which guards with op ? ...).

Suggestion:

Suggested change

	bool OpClassifierPass::shouldSkipCubeUpstream(Operation *op) {
	// arith dialect ops with tensor results are vector compute, not CUBE.
	if (isa<arith::ArithDialect>(op->getDialect())) {
	bool OpClassifierPass::shouldSkipCubeUpstream(Operation *op) {
	if (!op)
	return false;
	// arith dialect ops with tensor results are vector compute, not CUBE.
	if (isa<arith::ArithDialect>(op->getDialect())) {