FindMatlab: Use pre-built libraries for MinGW if needed

Modules/FindMatlab.cmake

@@ -1287,7 +1287,11 @@ set(Matlab_EXTERN_LIBRARY_DIR
     ${Matlab_ROOT_DIR}/extern/lib/${_matlab_bin_prefix}${_matlab_current_suffix})
 
 if(WIN32)
-  set(_matlab_lib_dir_for_search ${Matlab_EXTERN_LIBRARY_DIR}/microsoft)
+  if(MINGW)
+    set(_matlab_lib_dir_for_search ${Matlab_EXTERN_LIBRARY_DIR}/mingw64)
+  else()
+    set(_matlab_lib_dir_for_search ${Matlab_EXTERN_LIBRARY_DIR}/microsoft)
+  endif()
   set(_matlab_lib_prefix_for_search "lib")
 else()
   set(_matlab_lib_dir_for_search ${Matlab_BINARIES_DIR})