refactor(SBuffer, StoreDifftest): move diff store

[skyhgzsh]

event calculate part from scala to cpp

BREAKING CHANGE: struct DifftestStoreEvent is
changed and broke backward compatibility!

[Copilot]

Pull request overview

This PR refactors DiffTest store-event handling by moving store event “calculation/normalization” logic from the Scala side into the C++ checker, along with a breaking change to the DifftestStoreEvent/StoreEvent payload shape.

Changes:

• Replace pre-computed store event fields (addr/data/mask/eew/...) with raw fields and flags in StoreEvent (Scala bundle).
• Recompute effective store address/data/mask in StoreRecorder::check() (C++) based on the new raw fields.
• Adjust vector-store commit splitting to use the newly computed “VSLine” classification.

Reviewed changes

Copilot reviewed 2 out of 2 changed files in this pull request and generated 7 comments.

File	Description
src/test/csrc/difftest/checkers/store.cpp	Adds C++-side store-event normalization logic (mask expansion, address/data/mask derivation) and updates commit splitting inputs.
src/main/scala/Bundles.scala	Redefines StoreEvent bundle fields to carry raw store info and control flags instead of precomputed commit fields (breaking ABI change).

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[Copilot]

Pull request overview

Copilot reviewed 2 out of 2 changed files in this pull request and generated 3 comments.

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Pull request overview

Copilot reviewed 2 out of 2 changed files in this pull request and generated 2 comments.

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Pull request overview

Copilot reviewed 2 out of 2 changed files in this pull request and generated 1 comment.

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[Copilot]

Changing the vector-store path to if (calcIsVSLine) makes this block run whenever calcIsVSLine is true. In the downstream handleMisalign handling inside this block, refStoreCommitData is computed via shifts of (64 - (rawOffset * 8)); when offset % 8 == 0 (so rawOffset == 0), that code shifts by 64 bits, which is undefined behavior in C++. Please guard rawOffset == 0 (result should be 0) or rewrite the extraction using a mask to avoid shift-by-64 UB.