Increases size of llvm@6 by 2.5MiB (2.5%), but saves building specialized
llvm's with rtti enabled for packages that require RTTI when linking with the
llvm libraries.
* gnu/packages/llvm.scm (llvm-3.8-with-rtti): Remove variable.
(llvm)[arguments]: Add '-DLLVM_REQUIRES_RTTI=1' to #:configure-flags.
* gnu/packages/audio.scm (faust-2)[native-inputs]:
'llvm-3.8-with-rtti' -> 'llvm-3.8'.
fc9dbf4131