Merge pull request dotnet/coreclr#20132 from jkoritzinsky/fixes/coreclr/7829
authorJeremy Koritzinsky <jkoritzinsky@gmail.com>
Wed, 26 Sep 2018 22:38:24 +0000 (15:38 -0700)
committerGitHub <noreply@github.com>
Wed, 26 Sep 2018 22:38:24 +0000 (15:38 -0700)
Fix possible overflow in SafeBuffer.Initialize.

Commit migrated from https://github.com/dotnet/coreclr/commit/c7e9526b108c10360b71f7649e118831c54399ea


Trivial merge