Win32: bump submodule to v2.5.2.0
Win32: bump submodule to v2.5.2.0

Summary: This fixes the Windows build after the latest -Werror patches landed.

Test Plan: ./validate

Reviewers: austin, bgamari

Subscribers: rwbarton, thomie

Differential Revision: https://phabricator.haskell.org/D3293

ezyang/ghc,sdiehl/ghc,sdiehl/ghc,shlevy/ghc,ezyang/ghc,ezyang/ghc,shlevy/ghc,sdiehl/ghc,shlevy/ghc,ezyang/ghc,ezyang/ghc,shlevy/ghc,shlevy/ghc,sdiehl/ghc,shlevy/ghc,sdiehl/ghc,ezyang/ghc,shlevy/ghc,sdiehl/ghc,ezyang/ghc,sdiehl/ghc