How do I pass options to llc through clang?

I want to pass --enable-no-nans-fp-math to llc via clang. How should I do this? -X* doesn’t seem to help. I can dump .ll file with -S -emit-llvm but I would like to pass via clang something like
clang -llc --enable-no-nans-fp-math a.c.

Try to find the Clang driver option, as these are the supported interface. In this case, I think -fno-honor-nans is what you want.

You can pass options through to LLVM with -mllvm, but this is fragile, best effort, and can easily break.