Fix most of the issues reported by the Visual Studio code analysis tool.

cJSON.c

@@ -324,7 +324,7 @@ loop_end:
     {
         item->valueint = INT_MAX;
     }
-    else if (number <= INT_MIN)
+    else if (number <= (double)INT_MIN)
     {
         item->valueint = INT_MIN;
     }
@@ -346,7 +346,7 @@ CJSON_PUBLIC(double) cJSON_SetNumberHelper(cJSON *object, double number)
     {
         object->valueint = INT_MAX;
     }
-    else if (number <= INT_MIN)
+    else if (number <= (double)INT_MIN)
     {
         object->valueint = INT_MIN;
     }
@@ -1675,7 +1675,7 @@ static cJSON_bool print_object(const cJSON * const item, printbuffer * const out
         update_offset(output_buffer);
 
         /* print comma if not last */
-        length = (size_t) ((output_buffer->format ? 1 : 0) + (current_item->next ? 1 : 0));
+        length = ((size_t)(output_buffer->format ? 1 : 0) + (size_t)(current_item->next ? 1 : 0));
         output_pointer = ensure(output_buffer, length + 1);
         if (output_pointer == NULL)
         {
@@ -2300,7 +2300,7 @@ CJSON_PUBLIC(cJSON *) cJSON_CreateNumber(double num)
         {
             item->valueint = INT_MAX;
         }
-        else if (num <= INT_MIN)
+        else if (num <= (double)INT_MIN)
         {
             item->valueint = INT_MIN;
         }