lli: Add stub -use-mcjit option, which doesn't currently do anything.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@119508 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/ExecutionEngine/ExecutionEngine.cpp b/lib/ExecutionEngine/ExecutionEngine.cpp
index fc5cb92..91d68fb 100644
--- a/lib/ExecutionEngine/ExecutionEngine.cpp
+++ b/lib/ExecutionEngine/ExecutionEngine.cpp
@@ -46,6 +46,16 @@
   StringRef MArch,
   StringRef MCPU,
   const SmallVectorImpl<std::string>& MAttrs) = 0;
+ExecutionEngine *(*ExecutionEngine::MCJITCtor)(
+  Module *M,
+  std::string *ErrorStr,
+  JITMemoryManager *JMM,
+  CodeGenOpt::Level OptLevel,
+  bool GVsWithCode,
+  CodeModel::Model CMM,
+  StringRef MArch,
+  StringRef MCPU,
+  const SmallVectorImpl<std::string>& MAttrs) = 0;
 ExecutionEngine *(*ExecutionEngine::InterpCtor)(Module *M,
                                                 std::string *ErrorStr) = 0;
 
@@ -430,7 +440,13 @@
   // Unless the interpreter was explicitly selected or the JIT is not linked,
   // try making a JIT.
   if (WhichEngine & EngineKind::JIT) {
-    if (ExecutionEngine::JITCtor) {
+    if (UseMCJIT && ExecutionEngine::MCJITCtor) {
+      ExecutionEngine *EE =
+        ExecutionEngine::MCJITCtor(M, ErrorStr, JMM, OptLevel,
+                                   AllocateGVsWithCode, CMModel,
+                                   MArch, MCPU, MAttrs);
+      if (EE) return EE;
+    } else if (ExecutionEngine::JITCtor) {
       ExecutionEngine *EE =
         ExecutionEngine::JITCtor(M, ErrorStr, JMM, OptLevel,
                                  AllocateGVsWithCode, CMModel,