Plus additional ones needed by the routines added below:
copyright.h
random.h
The rest should have older access dates than your compile. And yes, you do need to include all the bsdf*.c files, along with a few other support routines. Here's the list of required C modules:
I hope I'm not forgetting anything. I know it's a lot, but still much less than the entire Radiance common library. A good test that you got everything is to compile these modules together to create testBSDF:
Documentation: https://developer.mozilla.org/en-US/docs/WebAssembly/C_to_wasm
From Greg's email to @andyrew: