evm: add "count leading zeros" opcode example

[ScottyPoi]

PR #4133 added support for the new CLZ (count leading zeros) opcode from EIP-7939.

The CLZ opcode (0x1e) pops one 256-bit word (x) from the stack and pushes the number of leading zero bits in x.

This PR adds a small example script to demonstrate the opcode in action. It creates an Osaka hardfork EVM with EIP-7939 enabled and executes the CLZ opcode on a few different 32-byte inputs.

Added subfolder evm/examples/opcodes and updated example runner script to run examples in the new subfolder

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 75.62%. Comparing base (6d6a6ba) to head (58f5aee).
⚠️ Report is 1 commits behind head on master.

Additional details and impacted files

Flag	Coverage Δ
block	88.43% <ø> (ø)
blockchain	88.85% <ø> (ø)
common	93.38% <ø> (ø)
evm	62.03% <ø> (ø)
mpt	90.86% <ø> (+1.07%)	⬆️
statemanager	78.10% <ø> (ø)
static	91.35% <ø> (ø)
tx	88.07% <ø> (ø)
util	84.94% <ø> (ø)
vm	65.10% <ø> (ø)

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[Copilot]

Pull Request Overview

This PR adds a new example demonstrating the CLZ (Count Leading Zeros) opcode introduced in EIP-7939 for the Osaka hardfork. The example shows how to use the new opcode with various test cases.

• Adds a comprehensive example file showcasing the CLZ opcode functionality
• Demonstrates four test cases covering edge cases: all zeros, minimal value, and different bit positions
• Uses manual bytecode assembly to construct and execute CLZ operations

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[holgerd77]

Can we make the name of this file more expressive, so that people can spot what the example is about?
(clz might be in the head of people now, but will be forgotten soon).

So that would be clz-opcode.ts or so.
(simple solution)

I you want to go a little extra mile I would also be a fan of the a bit extended version, which would be to keep the name but do a subfolder opcodes (like precompiles).

I prepared for that to be possible (in the sense that the examples still run), this would need a slight addition to the package.json examples script (should be obvious).

[holgerd77]

Nice, I have posted a few optimizations, but generally looks good! 🙂