* CMakeLists.txt: Enable CMP0092 if supported: MSVC warning flags are not in
  CMAKE_<LANG>_FLAGS by default.

git-svn-id: https://svn.apache.org/repos/asf/serf/trunk@1909249 13f79535-47bb-0310-9956-ffa450edef68
diff --git a/CMakeLists.txt b/CMakeLists.txt
index d12271c..537f186 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -35,6 +35,12 @@
   cmake_policy(SET CMP0074 NEW)
 endif()
 
+# Enable CMP0092 if supported: MSVC warning flags are not in
+# CMAKE_<LANG>_FLAGS by default.
+if(POLICY CMP0092)
+  cmake_policy(SET CMP0092 NEW)
+endif()
+
 set(SERF_SOURCE_DIR "${CMAKE_CURRENT_SOURCE_DIR}")
 set(CMAKE_MODULE_PATH "${SERF_SOURCE_DIR}/build")
 include(SerfVersion)