Fix llvm::MemoryBufferRef call for LLVM 3.6-
Fix llvm::MemoryBufferRef call for LLVM 3.6-

GuapoTaco/chigraph,russelltg/chigraph,chigraph/chigraph,chigraph/chigraph,chigraph/chigraph,russelltg/chigraph,GuapoTaco/chigraph