ac: fix build with recent LLVM

from Samuel Pitoiset
ee9811a0bb86d3d75fafeece368f6182048807d0 in mainline Mesa

lib/mesa/src/amd/common/ac_llvm_helper.cpp

@@ -197,7 +197,11 @@ struct ac_compiler_passes *ac_create_llvm_passes(LLVMTargetMachineRef tm)
 
 	if (TM->addPassesToEmitFile(p->passmgr, p->ostream,
 				    nullptr,
+#if HAVE_LLVM >= 0x1000
+				    llvm::CGFT_ObjectFile)) {
+#else
 				    llvm::TargetMachine::CGFT_ObjectFile)) {
+#endif
 		fprintf(stderr, "amd: TargetMachine can't emit a file of this type!\n");
 		delete p;
 		return NULL;