Revert "Implement NSDate as a small object (tagged pointer) - clang/libobjc2 only (#451)" because of GUI breakage: apps hang when loading NSMenu

This reverts commit 8fd2c06ddd.

Source/NSCalendarDate.m

@@ -58,6 +58,9 @@
 @class	GSAbsTimeZone;
 @interface	GSAbsTimeZone : NSObject	// Help the compiler
 @end
+@class	NSGDate;
+@interface	NSGDate : NSObject	// Help the compiler
+@end
 
 
 #define DISTANT_FUTURE	63113990400.0
@@ -393,6 +396,7 @@ GSPrivateTimeNow(void)
       absAbrIMP = (NSString* (*)(id,SEL,id))
 	[absClass instanceMethodForSelector: abrSEL];
 
+      GSObjCAddClassBehavior(self, [NSGDate class]);
       [pool release];
     }
 }
@@ -459,11 +463,6 @@ GSPrivateTimeNow(void)
   return AUTORELEASE(d);
 }
 
-- (NSTimeInterval) timeIntervalSinceReferenceDate
-{
-  return _seconds_since_ref;
-}
-
 /**
  * Creates and returns a new NSCalendarDate object by taking the
  * value of the receiver and adding the interval in seconds specified.

Source/NSDatePrivate.h

@@ -1,41 +0,0 @@
-/** NSDate Private Interface
-   Copyright (C) 2024 Free Software Foundation, Inc.
-
-   Written by: Hugo Melder <hugo@algoriddim.com>
-
-   This file is part of the GNUstep Base Library.
-
-   This library is free software; you can redistribute it and/or
-   modify it under the terms of the GNU Lesser General Public
-   License as published by the Free Software Foundation; either
-   version 2 of the License, or (at your option) any later version.
-
-   This library is distributed in the hope that it will be useful,
-   but WITHOUT ANY WARRANTY; without even the implied warranty of
-   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
-   Lesser General Public License for more details.
-
-   You should have received a copy of the GNU Lesser General Public
-   License along with this library; if not, write to the Free
-   Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
-   Boston, MA 02110 USA.
-*/
-
-#import <Foundation/NSDate.h>
-
-#if defined(OBJC_SMALL_OBJECT_SHIFT) && (OBJC_SMALL_OBJECT_SHIFT == 3)
-#define USE_SMALL_DATE 1
-#define DATE_CONCRETE_CLASS_NAME GSSmallDate
-#else
-#define USE_SMALL_DATE 0
-#define DATE_CONCRETE_CLASS_NAME NSGDate
-#endif
-
-@interface DATE_CONCRETE_CLASS_NAME : NSDate
-#if USE_SMALL_DATE == 0
-{
-@public
-  NSTimeInterval _seconds_since_ref;
-}
-#endif
-@end

Source/NSTimer.m

@@ -35,8 +35,9 @@
 #import "Foundation/NSRunLoop.h"
 #import "Foundation/NSInvocation.h"
 
-#import "NSDatePrivate.h"
-
+@class	NSGDate;
+@interface NSGDate : NSObject	// Help the compiler
+@end
 static Class	NSDate_class;
 
 /**
@@ -57,7 +58,7 @@ static Class	NSDate_class;
 {
   if (self == [NSTimer class])
     {
-      NSDate_class = [DATE_CONCRETE_CLASS_NAME class];
+      NSDate_class = [NSGDate class];
     }
 }