Summary:
Fixes https://github.com/facebook/react-native/issues/11861 - the release config is currently broken for projects created by `react-native init` in `master`, 0.40 and 0.39.
I'm still investigating when and how this got broken but this seems to be a clean fix. I've added `-ObjC` as well to match the main target but I'm not sure yet whether that's necessary.
To test:
```
react-native init fooproject --version react-native@rh389/react-native#missinglinkerflags
```
Open in XCode, Edit scheme (⌘<), Change `Build Configuration` to `Release`, build.
Update: The `-lc++` flag became necessary when 33deaad196 landed because of the libstdc++ dependencies of `RCTLog`. Still not sure about `-ObjC`. javache ?
Closes https://github.com/facebook/react-native/pull/11889
Differential Revision: D4421685
Pulled By: javache
fbshipit-source-id: 954edaef773f8cef7b7ad671fa4d1f2bfc2f20f2
e0c3d56d3a