Testbench

[n0thingNoob]

Add -o3 to the histogram test.

[Copilot]

Pull Request Overview

This PR updates the histogram test to use -O3 optimization level and enhances the pass pipeline with additional optimization passes. The change addresses a previous issue with higher optimization levels by adding specific flags to disable vectorization and loop unrolling.

Key changes:

• Compilation flags updated from -O2 to -O3 with vectorization and loop unrolling disabled
• Pass pipeline reorganized with --promote-func-arg-to-const and --fold-constant moved earlier and duplicated
• Architecture spec path simplified to use relative path
• Expected output patterns updated to reflect the new compilation results

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