message: PCH: disable by default on all platforms except MSVC
diff: @@ -475,7 +475,7 @@ OCV_OPTION(INSTALL_TESTS "Install accuracy and performance test binar
  # OpenCV build options
  # ===================================================
  OCV_OPTION(ENABLE_CCACHE "Use ccache" (UNIX AND NOT IOS AND (CMAKE_GENERATOR MATCHES "Makefile" OR CMAKE_GENERATOR MATCHES "Ninja")) )
  -OCV_OPTION(ENABLE_PRECOMPILED_HEADERS "Use precompiled headers" ON IF (MSVC OR (NOT IOS AND NOT CMAKE_CROSSCOMPILING) ) )
  +OCV_OPTION(ENABLE_PRECOMPILED_HEADERS "Use precompiled headers" MSVC IF (MSVC OR (NOT IOS AND NOT CMAKE_CROSSCOMPILING) ) )
  OCV_OPTION(ENABLE_SOLUTION_FOLDERS "Solution folder in Visual Studio or in other IDEs" (MSVC_IDE OR CMAKE_GENERATOR MATCHES Xcode) )
  OCV_OPTION(ENABLE_PROFILING "Enable profiling in the GCC compiler (Add flags: -g -pg)" OFF IF CV_GCC )
  OCV_OPTION(ENABLE_COVERAGE "Enable coverage collection with GCov" OFF IF CV_GCC )
  