Nuke the old JIT.

I am sure we will be finding bits and pieces of dead code for years to
come, but this is a good start.

Thanks to Lang Hames for making MCJIT a good replacement!

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@215111 91177308-0d34-0410-b5e6-96231b3b80d8

examples/Kaleidoscope/MCJIT/initial/toy.cpp

@@ -778,7 +778,6 @@ void *MCJITHelper::getPointerToFunction(Function* F) {
     std::string ErrStr;
     ExecutionEngine *NewEngine = EngineBuilder(OpenModule)
                                               .setErrorStr(&ErrStr)
-                                              .setUseMCJIT(true)
                                               .setMCJITMemoryManager(new HelpingMemoryManager(this))
                                               .create();
     if (!NewEngine) {