Make appendCallNB lambda mutable

[beanz]

Summary

Lambdas are by deafult const so that they produce the same output every time they are run. This lambda needs to set the value on a captured promise which is a mutating operation, so it must be mutable.

[beanz]

Accidentally uploaded this

llvm/include/llvm/ExecutionEngine/Orc/RPCUtils.h

Expected<NonBlockingCallResult<Func>> appendCallNB(const ArgTs &... Args) {
     using RTraits = detail::ResultTraits<typename Func::ReturnType>;
     using ErrorReturn = typename RTraits::ErrorReturnType;
     using ErrorReturnPromise = typename RTraits::ReturnPromiseType;
 
     ErrorReturnPromise Promise;
     auto FutureResult = Promise.get_future();
 
     if (auto Err = this->template appendCallAsync<Func>(
-            [Promise = std::move(Promise)](ErrorReturn RetOrErr) {
+            [Promise = std::move(Promise)](ErrorReturn RetOrErr) mutable {
               Promise.set_value(std::move(RetOrErr));
               return Error::success();
             },
             Args...)) {
       RTraits::consumeAbandoned(FutureResult.get());
       return std::move(Err);
     }
     return std::move(FutureResult);