Merge pull request #5246 from mshabunin:ccache-fix

cmake/OpenCVDetectCXXCompiler.cmake

@@ -13,8 +13,11 @@ if(CMAKE_C_COMPILER_ID STREQUAL "Clang")
   set(CMAKE_COMPILER_IS_GNUCC 1)
   set(CMAKE_COMPILER_IS_CLANGCC 1)
 endif()
+if("${CMAKE_CXX_COMPILER};${CMAKE_C_COMPILER}" MATCHES "ccache")
+  set(CMAKE_COMPILER_IS_CCACHE 1)
+endif()
 
-if((CMAKE_COMPILER_IS_CLANGCXX OR CMAKE_COMPILER_IS_CLANGCC) AND NOT CMAKE_GENERATOR MATCHES "Xcode")
+if((CMAKE_COMPILER_IS_CLANGCXX OR CMAKE_COMPILER_IS_CLANGCC OR CMAKE_COMPILER_IS_CCACHE) AND NOT CMAKE_GENERATOR MATCHES "Xcode")
   set(ENABLE_PRECOMPILED_HEADERS OFF CACHE BOOL "" FORCE)
 endif()