This runs just fine.

gistfile1.c

#include <stdbool.h>
#include <stdio.h>

#include <llvm-c/Core.h>
#include <llvm-c/ExecutionEngine.h>

int main(int argc, char **argv) {
  LLVMLinkInJIT();
  if (LLVMInitializeNativeTarget()) {
    fprintf(stderr, "Failed to initialize native target.\n");
  }

  // first, create a module
  LLVMModuleRef module = LLVMModuleCreateWithName("myModule");

  // add a function
  LLVMValueRef function = LLVMAddFunction
    ( module
    , "myFunction"
    , LLVMFunctionType
      ( LLVMInt64Type()
      , (LLVMTypeRef[2]){LLVMInt64Type(), LLVMInt64Type()}, 2
      , false
      ));

  LLVMBasicBlockRef block = LLVMAppendBasicBlock(function, "myBlock");

  LLVMBuilderRef builder = LLVMCreateBuilder();
  LLVMPositionBuilderAtEnd(builder, block);

  LLVMValueRef temp = LLVMBuildAdd
    ( builder
    , LLVMGetParam(function, 0), LLVMGetParam(function, 1)
    , "add");
  LLVMBuildRet(builder, temp);

  // create an execution engine
  LLVMExecutionEngineRef engine;
  char *error;
  if (LLVMCreateJITCompilerForModule(&engine, module, 0, &error)) {
    fprintf(stderr, "%s\n", error);
  }

  unsigned long long result = LLVMGenericValueToInt
    ( LLVMRunFunction
      ( engine
      , function
      , 2, (LLVMGenericValueRef[2])
        { LLVMCreateGenericValueOfInt(LLVMInt64Type(), 42, false)
        , LLVMCreateGenericValueOfInt(LLVMInt64Type(), 3, false)
        }
      )
    , 0
    );

  printf("result = %llu\n", result);

  return 0;
}