Implement SIMD

[mohanson]

Adds SIMD (Single Instruction, Multiple Data) support for the pywasm.

[Copilot]

Pull Request Overview

Implements SIMD (Single Instruction, Multiple Data) support for the pywasm WebAssembly interpreter, adding v128 vector operations and arithmetic utilities.

• Adds comprehensive SIMD opcode definitions for v128 vector operations including load/store, lane operations, and arithmetic operations
• Introduces a new arithmetic module with integer and floating-point arithmetic helper classes for proper value fitting and operations
• Updates the test framework to support SIMD-specific test files and enhance value comparison for v128 types

Reviewed Changes

Copilot reviewed 11 out of 15 changed files in this pull request and generated 2 comments.

Show a summary per file

File	Description
pywasm/opcode.py	Adds 236 new SIMD opcodes and their string mappings for v128 vector operations
pywasm/arith.py	New arithmetic utility module with signed/unsigned integer and floating-point arithmetic classes
test/spec.py	Updates test framework to handle v128 values and includes SIMD test files
script/build_spec.py	Extends build script to process SIMD-specific test files
pywasm/init.py	Exposes the new arithmetic module
example/	Adds blake2b SIMD example with Rust implementation and Python test
README.md	Documents the new blake2b SIMD example

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[Copilot]

The recursive call to vale should pass individual elements, not lists. Change to if all([vale(xi, yi) for xi, yi in zip(x, y)]):.

Suggested change

	if all([vale(x, y) for x, y in zip(x, y)]):
	return True
	x = [pywasm.core.ValInst.from_f64(e) for e in a.into_v128_f64()]
	y = [pywasm.core.ValInst.from_f64(e) for e in b.into_v128_f64()]
	if all([vale(x, y) for x, y in zip(x, y)]):
	if all([vale(xi, yi) for xi, yi in zip(x, y)]):
	return True
	x = [pywasm.core.ValInst.from_f64(e) for e in a.into_v128_f64()]
	y = [pywasm.core.ValInst.from_f64(e) for e in b.into_v128_f64()]
	if all([vale(xi, yi) for xi, yi in zip(x, y)]):

[Copilot]

The recursive call to vale should pass individual elements, not lists. Change to if all([vale(xi, yi) for xi, yi in zip(x, y)]):.

Suggested change

	if all([vale(x, y) for x, y in zip(x, y)]):
	if all([vale(xi, yi) for xi, yi in zip(x, y)]):