Merge pull request dotnet/corefx#33104 from stephentoub/exposeasync
authorStephen Toub <stoub@microsoft.com>
Thu, 8 Nov 2018 02:14:46 +0000 (21:14 -0500)
committerGitHub <noreply@github.com>
Thu, 8 Nov 2018 02:14:46 +0000 (21:14 -0500)
Expose async iterator-related types

Commit migrated from https://github.com/dotnet/corefx/commit/637e109e7d085b8c01b5ba22521c021f8204ff12


Trivial merge