ChaiScript relies heavily on C++ exceptions for error propagation, but
the Emscripten build was missing the -fwasm-exceptions flag. Without it,
any C++ exception in the WASM module causes an abort instead of being
catchable by JavaScript. Added -fwasm-exceptions as both a compile and
link option, and added a regression test verifying exception propagation
through the eval wrapper functions.
Co-authored-by: leftibot <leftibot@users.noreply.github.com>
Co-authored-by: Claude Opus 4.6 (1M context) <noreply@anthropic.com>