[circt-synth] Add an option to disable WordsToBits, remove verification code from design

[uenoku]

This modifies circt-synth to make it more practical.

• Remove verification code from synthesis parts. ExtarctTestCode is currently used, but eventually it must be replaced with something cleaner.
• Add an option to disable wordsToBits.

[Copilot]

Pull Request Overview

This PR modifies circt-synth to make it more practical for synthesis by adding options to handle verification code and bit-blasting optimizations.

• Adds verification code extraction to move test code away from design modules for faster synthesis
• Introduces an option to disable WordsToBits transformation for better scalability with large designs
• Updates build dependencies to support the new verification code extraction functionality

Reviewed Changes

Copilot reviewed 5 out of 5 changed files in this pull request and generated 2 comments.

Show a summary per file

File	Description
tools/circt-synth/circt-synth.cpp	Adds SV header include and ExtractTestCode pass to synthesis pipeline
tools/circt-synth/CMakeLists.txt	Adds CIRCTSVTransforms dependency for ExtractTestCode pass
test/circt-synth/basic.mlir	Adds test case for the new disable-word-to-bits option
lib/Synthesis/SynthesisPipeline.cpp	Makes LowerWordToBits pass conditional based on options
include/circt/Synthesis/SynthesisPipeline.h	Defines disableWordToBits option in pipeline options

[maerhart]

LGTM