feat(slang): add assert built-in

[hedgar2017]

Wire up assert(condition) as a built-in function dispatch in CallEmitter.

Previously, assert() calls fell through to resolve_function and failed with "undefined function: assert".

Newly passing tests:

• tests/solidity/simple/fuzzed/boolean_assert.sol
• tests/solidity/simple/fuzzed/boolean_assert1.sol

[Copilot]

Pull request overview

This PR adds first-class lowering support for Solidity’s assert(condition) built-in in the slang frontend, emitting the Sol dialect sol.assert op instead of falling through to normal function resolution (which previously produced “undefined function: assert”).

Changes:

• Add assert built-in detection in CallEmitter::emit_function_call and lower it via a new emit_assert helper.
• Introduce Builder::emit_sol_assert to append a sol.assert operation.

Reviewed changes

Copilot reviewed 3 out of 3 changed files in this pull request and generated no comments.

File	Description
solx-slang/src/ast/contract/function/expression/call/mod.rs	Detects assert() calls and emits sol.assert with a boolean condition value.
solx-mlir/src/context/builder/mod.rs	Adds an MLIR builder helper to construct and append sol.assert.

[abinavpp]

Thank you!