Log Message:
Update to base-compat-0.11.2

Changes in 0.11.2 [2020.09.30]
* Sync with base-4.15/GHC 9.0
* Backport singleton to Data.List and Data.List.NonEmpty
* Backport hGetContents', getContents', and readFile' added to System.IO

Changes in 0.11.1 [2020.01.27]
* Sync with base-4.14/GHC 8.10
* Backport isResourceVanishedError, resourceVanishedErrorType, and
  isResourceVanishedErrorType to System.IO.Error.Compat.