Make FutureRequest::processClientInterceptorsAndExtractResult noexcept

Summary: It's returning a `folly::Try` should the function itself should avoid throwing. `extractResult` can throw if the RPC threw an exception.

Reviewed By: iahs

Differential Revision: D62657033

fbshipit-source-id: 1ffa8b14f2a6f02c227f7f2c5aaa2ece10f013ba

thrift/lib/cpp2/async/FutureRequest.h

@@ -76,7 +76,7 @@ class FutureCallbackHelper {
  }
 
  static folly::Try<Result> processClientInterceptorsAndExtractResult(
- PromiseResult&& result) {
+ PromiseResult&& result) noexcept {
  apache::thrift::ClientReceiveState clientReceiveState =
  extractClientReceiveState(result);
  auto* contextStack = clientReceiveState.ctx();
@@ -86,7 +86,7 @@ class FutureCallbackHelper {
  return folly::Try<Result>(std::move(exTry).exception());
  }
  }
- return folly::Try<Result>(extractResult(std::move(result)));
+ return folly::makeTryWith([&] { return extractResult(std::move(result)); });
  }
 };