message: cmake: drop amending of compilation options
  Allow to specify optimization level via CMake.
diff: @@ -28,17 +28,6 @@ if((CMAKE_COMPILER_IS_CLANGCXX OR CMAKE_COMPILER_IS_CLANGCC OR CMAKE_COMPILER_IS
  set(ENABLE_PRECOMPILED_HEADERS OFF CACHE BOOL "" FORCE)
  endif()
  -if(MINGW OR (X86 AND UNIX AND NOT APPLE))
  - # mingw compiler is known to produce unstable SSE code with -O3 hence we are trying to use -O2 instead
  - if(CMAKE_COMPILER_IS_GNUCXX)
  - foreach(flags
  - CMAKE_CXX_FLAGS CMAKE_CXX_FLAGS_RELEASE CMAKE_CXX_FLAGS_DEBUG
  - CMAKE_C_FLAGS CMAKE_C_FLAGS_RELEASE CMAKE_C_FLAGS_DEBUG)
  - string(REPLACE "-O3" "-O2" ${flags} "${${flags}}")
  - endforeach()
  - endif()
  -endif()
  -
  if(MSVC)
  string(STRIP "${CMAKE_CXX_FLAGS}" CMAKE_CXX_FLAGS)
  string(STRIP "${CMAKE_CXX_FLAGS_INIT}" CMAKE_CXX_FLAGS_INIT)
  