Summary:
This intentionally leaks the static map, since it still might be accessed after static destructors are run. This is a common approach to this problem, see https://github.com/facebook/react-native/pull/22607 and https://github.com/facebook/componentkit/pull/906 as examples. It also sets up an autorelease pool from `RCTNativeModule::invoke` as a precaution since there's no strict guarantee one exists when it is called.
Changelog:
[iOS][Fixed] - Fix crash in RCTCoreModulesClassProvider during quit
Reviewed By: RSNara
Differential Revision: D27932062
fbshipit-source-id: fa75da4b78290027a762440ac6943c81b8594a57