* gnu/packages/audio.scm (faust-2): Update to 2.5.23.
[native-inputs]: Replace llvm-with-rtti with llvm-3.8-with-rtti.
* gnu/packages/llvm.scm (llvm-with-rtti): Rename this variable...
(llvm-3.8-with-rtti): ...to this variable; inherit from llvm-3.8.