Reinstate "Nuke the old JIT."

Approved by Jim Grosbach, Lang Hames, Rafael Espindola.

This reinstates commits r215111, 215115, 215116, 215117, 215136.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@216982 91177308-0d34-0410-b5e6-96231b3b80d8

lib/ExecutionEngine/ExecutionEngineBindings.cpp

@@ -184,7 +184,6 @@ LLVMBool LLVMCreateMCJITCompilerForModule(
   EngineBuilder builder(std::unique_ptr<Module>(unwrap(M)));
   builder.setEngineKind(EngineKind::JIT)
          .setErrorStr(&Error)
-         .setUseMCJIT(true)
          .setOptLevel((CodeGenOpt::Level)options.OptLevel)
          .setCodeModel(unwrap(options.CodeModel))
          .setTargetOptions(targetOptions);
@@ -267,7 +266,6 @@ LLVMGenericValueRef LLVMRunFunction(LLVMExecutionEngineRef EE, LLVMValueRef F,
 }
 
 void LLVMFreeMachineCodeForFunction(LLVMExecutionEngineRef EE, LLVMValueRef F) {
-  unwrap(EE)->freeMachineCodeForFunction(unwrap<Function>(F));
 }
 
 void LLVMAddModule(LLVMExecutionEngineRef EE, LLVMModuleRef M){
@@ -306,7 +304,7 @@ LLVMBool LLVMFindFunction(LLVMExecutionEngineRef EE, const char *Name,
 
 void *LLVMRecompileAndRelinkFunction(LLVMExecutionEngineRef EE,
                                      LLVMValueRef Fn) {
-  return unwrap(EE)->recompileAndRelinkFunction(unwrap<Function>(Fn));
+  return nullptr;
 }
 
 LLVMTargetDataRef LLVMGetExecutionEngineTargetData(LLVMExecutionEngineRef EE) {