Option for compiling stdlib with debug symbols

By default, Emscripten compiles the C/C++ standard libraries without debug symbols. This can be checked by running llvm-dwarfdump on files from upstream/emscripten/cache/sysroot/lib/wasm32-emscripten/.
This causes troubles when debugging crashes that happen inside the standard library functions.

Can there be a simple way for forcing debug symbols (`-g`) in the standard library built by Emscripten?

The current workaround is, for example, to hack emcc.py to always specify `-g` regardless of the input parameters.