Adapt jit-rt to LLVM 9

runtime/jit-rt/DefineBuildJitRT.cmake

@@ -53,8 +53,13 @@ if(LDC_DYNAMIC_COMPILE)
         # to do find_package(LLVM CONFIG) for it so here is a hackish way to get it
         include("${LLVM_CMAKEDIR}/LLVMConfig.cmake")
         include("${LLVM_CMAKEDIR}/LLVM-Config.cmake")
+
+        set(asmprinter "asmprinter")
+        if(LDC_LLVM_VER LESS 900)
+            set(asmprinter "${LLVM_NATIVE_ARCH}asmprinter")
+        endif()
         llvm_map_components_to_libnames(JITRT_LLVM_LIBS core support irreader executionengine passes nativecodegen orcjit target
-            "${LLVM_NATIVE_ARCH}disassembler" "${LLVM_NATIVE_ARCH}asmprinter")
+            "${LLVM_NATIVE_ARCH}disassembler" "${asmprinter}")
 
         foreach(libname ${JITRT_LLVM_LIBS})
             unset(JITRT_TEMP_LIB CACHE)

runtime/jit-rt/cpp-so/disassembler.cpp

@@ -323,7 +323,13 @@ void disassemble(const llvm::TargetMachine &tm,
     if (object.section_end() != secIt) {
       const auto sec = *secIt;
       llvm::StringRef data;
+#if LDC_LLVM_VER >= 900
+      auto dataOrError = sec.getContents();
+      assert(dataOrError);
+      data = *dataOrError;
+#else
       sec.getContents(data);
+#endif
 
       if (llvm::object::SymbolRef::ST_Function ==
           llvm::cantFail(symbol.getType())) {

runtime/jit-rt/cpp-so/optimizer.cpp

@@ -138,7 +138,9 @@ void addOptimizationPasses(llvm::legacy::PassManagerBase &mpm,
     builder.Inliner = llvm::createAlwaysInlinerPass();
 #endif
   }
+#if LDC_LLVM_VER < 900
   builder.DisableUnitAtATime = false;
+#endif
 
   builder.DisableUnrollLoops = (disableLoopUnrolling.getNumOccurrences() > 0)
                                    ? disableLoopUnrolling