[CUDA] Fix build for LLVM 7.0
The `addPassesToEmitFile` function has an additional argument.
@@ -135,6 +135,9 @@ int pocl_ptx_gen(const char *BitcodeFilename, const char *PTXFilename,
llvm::SmallVector<char, 4096> Data;
llvm::raw_svector_ostream PTXStream(Data);
if (Machine->addPassesToEmitFile(Passes, PTXStream,
+#if ! LLVM_OLDER_THAN_7_0
+ nullptr,
+#endif
llvm::TargetMachine::CGFT_AssemblyFile)) {
POCL_MSG_ERR("[CUDA] ptx-gen: failed to add passes\n");
return 1;
