llvm6: CodeModel::{JIT,}Default no longer exists

LLVM has since removed the `CodeModel::Default` enum value in favor of an
`Optional` implementationg throughout LLVM. Let's mirror the same change in Rust
and update the various bindings we call accordingly.

Removed in llvm-mirror/llvm@9aafb854c

src/rustllvm/PassWrapper.cpp

@@ -23,9 +23,14 @@
 #include "llvm/Support/FileSystem.h"
 #include "llvm/Support/Host.h"
 #include "llvm/Target/TargetMachine.h"
-#include "llvm/Target/TargetSubtargetInfo.h"
 #include "llvm/Transforms/IPO/PassManagerBuilder.h"
 
+#if LLVM_VERSION_GE(6, 0)
+#include "llvm/CodeGen/TargetSubtargetInfo.h"
+#else
+#include "llvm/Target/TargetSubtargetInfo.h"
+#endif
+
 #if LLVM_VERSION_GE(4, 0)
 #include "llvm/Transforms/IPO/AlwaysInliner.h"
 #include "llvm/Transforms/IPO/FunctionImport.h"
@@ -210,20 +215,15 @@ extern "C" bool LLVMRustHasFeature(LLVMTargetMachineRef TM,
 
 enum class LLVMRustCodeModel {
   Other,
-  Default,
-  JITDefault,
   Small,
   Kernel,
   Medium,
   Large,
+  None,
 };
 
 static CodeModel::Model fromRust(LLVMRustCodeModel Model) {
   switch (Model) {
-  case LLVMRustCodeModel::Default:
-    return CodeModel::Default;
-  case LLVMRustCodeModel::JITDefault:
-    return CodeModel::JITDefault;
   case LLVMRustCodeModel::Small:
     return CodeModel::Small;
   case LLVMRustCodeModel::Kernel:
@@ -360,7 +360,6 @@ extern "C" LLVMTargetMachineRef LLVMRustCreateTargetMachine(
     bool TrapUnreachable,
     bool Singlethread) {
 
-  auto CM = fromRust(RustCM);
   auto OptLevel = fromRust(RustOptLevel);
   auto RM = fromRust(RustReloc);
 
@@ -399,6 +398,13 @@ extern "C" LLVMTargetMachineRef LLVMRustCreateTargetMachine(
     Options.ThreadModel = ThreadModel::Single;
   }
 
+#if LLVM_VERSION_GE(6, 0)
+  Optional<CodeModel::Model> CM;
+#else
+  CodeModel::Model CM = CodeModel::Model::Default;
+#endif
+  if (RustCM != LLVMRustCodeModel::None)
+    CM = fromRust(RustCM);
   TargetMachine *TM = TheTarget->createTargetMachine(
       Trip.getTriple(), RealCPU, Feature, Options, RM, CM, OptLevel);
   return wrap(TM);