THRIFT-2850 CMake: improve Windows support

use YY_NO_UNISTD_H and remove --wincompat
diff --git a/build/cmake/DefinePlatformSpecifc.cmake b/build/cmake/DefinePlatformSpecifc.cmake
index 515bb18..db411d5 100644
--- a/build/cmake/DefinePlatformSpecifc.cmake
+++ b/build/cmake/DefinePlatformSpecifc.cmake
@@ -65,7 +65,7 @@
     # Windows build does not know how to make a shared library yet
     # as there are no __declspec(dllexport) or exports files in the project.
     if (WITH_SHARED_LIB)
-        message (FATAL_ERROR "Windows build does not support shared library output yet!")
+      message (FATAL_ERROR "Windows build does not support shared library output yet, please set -DWITH_SHARED_LIB=off")
     endif()
 
 elseif(UNIX)