THRIFT-4159: enable some Windows sources also on MSYS2

This closes #1248
diff --git a/lib/cpp/CMakeLists.txt b/lib/cpp/CMakeLists.txt
index 9a1ef10..59da346 100755
--- a/lib/cpp/CMakeLists.txt
+++ b/lib/cpp/CMakeLists.txt
@@ -57,7 +57,7 @@
    src/thrift/server/TThreadedServer.cpp
 )
 
-# This files don't work on Windows CE as there is no pipe support
+# These files don't work on Windows CE as there is no pipe support
 # TODO: These files won't work with UNICODE support on windows. If fixed this can be re-added.
 if (NOT WINCE)
     list(APPEND thriftcpp_SOURCES
@@ -68,7 +68,7 @@
 endif()
 
 
-if (WIN32 AND NOT MSYS)
+if (WIN32)
     list(APPEND thriftcpp_SOURCES
         src/thrift/windows/TWinsockSingleton.cpp
         src/thrift/windows/SocketPair.cpp