[RAISE-BP] Remove mask for pointer tensor load/store operations

[mfrancepillois]

Subsequent lowering passes don't expect pointer tensor load/store operations to have a non-null mask operand.
This PR therefore remove the mask operand from the generated load/store operations.
If a load/store operation has a non-empty mask, the operation is not rewritten.
This PR also improve the robustness of the pass by adding a cast operation if size, shape or offset values of MakeTensorPtrOp are of type Index.

[victor-eds]

Changes LGTM. Should we then fail if we find a mask on tt.load/store?

[whitneywhtsang]

Why is it safe to simply remove mask from load and store?

[mfrancepillois]

Why is it safe to simply remove mask from load and store?

You're right. It not safe to simply remove mask. Issue #1784 has been created to address this problem.

[whitneywhtsang]

Why is it safe to simply remove mask from load and store?

You're right. It not safe to simply remove mask. Issue #1784 has been created to address this problem.

Do we still need to review this PR? Should it be closed?

[mfrancepillois]

Why is it safe to simply remove mask from load and store?

You're right. It not safe to simply remove mask. Issue #1784 has been created to address this problem.

Do we still need to review this PR? Should it be closed?

The changes in this PR are still needed as block pointer load/store ops are not in line with the triton ops spec.
The PR has been updated to generated only safe code until issue #1784 has been addressed.
i.e. if a load/store operation has a non-empty mask, the operation is not rewritten.