cmake: allow BUILD_FAT_JAVA_LIB for non-Android targets too

cmake/OpenCVModule.cmake

@@ -886,7 +886,10 @@ macro(_ocv_create_module)
     DEFINE_SYMBOL CVAPI_EXPORTS
   )
 
-  if(ANDROID AND BUILD_FAT_JAVA_LIB)
+  if(BUILD_FAT_JAVA_LIB)  # force exports from static modules too
+    if(BUILD_SHARED_LIBS)
+      message(FATAL_ERROR "Assertion failed: BUILD_SHARED_LIBS=OFF must be off if BUILD_FAT_JAVA_LIB=ON")
+    endif()
     target_compile_definitions(${the_module} PRIVATE CVAPI_EXPORTS)
   endif()
 

cmake/OpenCVUtils.cmake

@@ -452,6 +452,9 @@ macro(OCV_OPTION variable description value)
       option(${variable} "${description}" ${__value})
     endif()
   else()
+    if(DEFINED ${variable})
+      # TODO: message(WARNING "Option will be ignored: ${variable} (=${${variable}})")
+    endif()
     unset(${variable} CACHE)
   endif()
   unset(__condition)