Fixed mingw compilation on Windows

cmake/OpenCVPCHSupport.cmake

@@ -211,7 +211,7 @@ MACRO(ADD_PRECOMPILED_HEADER_TO_TARGET _targetName _input _pch_output_to_use )
 
     GET_TARGET_PROPERTY(_sources ${_targetName} SOURCES)
     FOREACH(src ${_sources})
-      if(NOT "${src}" MATCHES "\\.mm$")
+      if(NOT "${src}" MATCHES "\\.mm$" AND NOT "${src}" MATCHES "\\.rc$")
         get_source_file_property(_flags "${src}" COMPILE_FLAGS)
         get_source_file_property(_flags2 "${src}" COMPILE_DEFINITIONS)
         if(NOT _flags AND NOT _flags2)

modules/core/src/utils/filesystem.cpp

@@ -25,6 +25,7 @@
 
 #ifdef _WIN32
 #define WIN32_LEAN_AND_MEAN
+#undef NOMINMAX
 #define NOMINMAX
 #include <windows.h>
 #include <direct.h>