Make Conditionals.h a catch-all for old configs

Marlin/Conditionals.h → Marlin/Conditionals_post.h

  */
 
 /**
- * Conditionals.h
+ * Conditionals_post.h
  * Defines that depend on configuration but are not editable.
  */
 
-#ifndef CONDITIONALS_H
-#define CONDITIONALS_H
 
   #include "pins.h"
 
   #include "Arduino.h"
 
   #include "macros.h"
+#ifndef CONDITIONALS_POST_H
+#define CONDITIONALS_POST_H
 
   #if ENABLED(EMERGENCY_PARSER)
     #define EMERGENCY_PARSER_CAPABILITIES " EMERGENCY_CODES:M108,M112,M410"
     #define Z_RAISE_BETWEEN_PROBING MIN_Z_HEIGHT_FOR_HOMING
   #endif
 
-#endif //CONDITIONALS_H
+#endif // CONDITIONALS_POST_H

Marlin/MarlinConfig.h

 #include "Configuration.h"
 #include "Conditionals_LCD.h"
 #include "Configuration_adv.h"
-#include "Conditionals.h"
+#include "Conditionals_post.h"
 #include "SanityCheck.h"
 
 #endif // MARLIN_CONFIG_H