Fixed number of warnings. Fixed mingw64 build.

modules/highgui/src/grfmt_jpeg.cpp

@@ -45,7 +45,8 @@
 #ifdef HAVE_JPEG
 
 #ifdef _MSC_VER
-#pragma warning(disable: 4324 4611)
+//interaction between '_setjmp' and C++ object destruction is non-portable
+#pragma warning(disable: 4611)
 #endif
 
 #include <stdio.h>
@@ -69,11 +70,18 @@ extern "C" {
 namespace cv
 {
 
+#ifdef _MSC_VER
+# pragma warning(push)
+# pragma warning(disable:4324) //structure was padded due to __declspec(align())
+#endif
 struct JpegErrorMgr
 {
     struct jpeg_error_mgr pub;
     jmp_buf setjmp_buffer;
 };
+#ifdef _MSC_VER
+# pragma warning(pop)
+#endif
 
 struct JpegSource
 {