SeExpr is an embeddable, arithmetic expression language that enables flexible artistic control and customization in creating computer graphics images. Example uses include procedural geometry synthesis, image synthesis, simulation control, crowd animation, and geometry deformation. https://wdas.github.io/SeExpr
Apparently, this functions is deprecated in current LLVM (4.0) and this appears missing during the build. (See https://github.com/llvm-mirror/llvm/blob/master/lib/Transforms/IPO/AlwaysInliner.cpp )
The functions was replaced by
llvm::createAlwaysInlinerLegacyPass, which can probably be called with a simple LLVM version preprocessor check.