Eliot Miranda uploaded a new version of Collections to project The Trunk:
http://source.squeak.org/trunk/Collections-eem.885.mcz

==================== Summary ====================

Name: Collections-eem.885
Author: eem
Time: 15 April 2020, 4:37:54.800631 pm
UUID: 45d219d3-6ed0-4401-a820-44eebe21d71a
Ancestors: Collections-eem.883, Collections-dtl.884

Switch elementsForwardIdentityTo: to not copy the hash, see http://forum.world.st/How-to-become-immediate-objects-td5114931.html.
Add elementsForwardIdentityAndHashTo: for the old behavior.

=============== Diff against Collections-dtl.884 ===============

Item was added:
+ ----- Method: Array>>elementsForwardIdentityAndHashTo: (in category 'converting') -----
+ elementsForwardIdentityAndHashTo: otherArray
+ 	"This primitive performs a bulk mutation, causing all pointers to the elements of the
+ 	 receiver to be replaced by pointers to the corresponding elements of otherArray.
+ 	 The identityHashes remain with the pointers rather than with the objects so that
+ 	 the objects in this array should still be properly indexed in any existing hashed
+ 	 structures after the mutation."
+ 	<primitive: 72 error: ec>
+ 	ec == #'no modification' ifTrue:
+ 		[^self modificationForbiddenFor: otherArray becomeSelector: #elementsForwardIdentityAndHashTo:].
+ 	ec == #'bad receiver' ifTrue:
+ 		[^self error: 'receiver must be of class Array'].
+ 	ec == #'bad argument' ifTrue:
+ 		[^self error: (otherArray class == Array
+ 						ifTrue: ['arg must be of class Array']
+ 						ifFalse: ['receiver and argument must have the same size'])].
+ 	ec == #'inappropriate operation' ifTrue:
+ 		[^self error: 'can''t become immediates such as SmallIntegers or Characters'].
+ 	ec == #'object is pinned' ifTrue:
+ 		[^self error: 'can''t become pinned objects'].
+ 	ec == #'insufficient object memory' ifTrue:
+ 		[self error: 'The virtual machine is out-of-date.  Please upgrade.'].
+ 	self primitiveFailed!

Item was changed:
  ----- Method: Array>>elementsForwardIdentityTo: (in category 'converting') -----
  elementsForwardIdentityTo: otherArray
  	"This primitive performs a bulk mutation, causing all pointers to the elements of the
  	 receiver to be replaced by pointers to the corresponding elements of otherArray.
+ 	 The identityHashes are not copied to the target objects so that the objects in otherArray
+ 	 should still be properly indexed in any existing hashed structures after the mutation."
+ 	<primitive: 248 error: ec>
- 	 The identityHashes remain with the pointers rather than with the objects so that
- 	 the objects in this array should still be properly indexed in any existing hashed
- 	 structures after the mutation."
- 	<primitive: 72 error: ec>
  	ec == #'no modification' ifTrue:
  		[^self modificationForbiddenFor: otherArray becomeSelector: #elementsForwardIdentityTo:].
  	ec == #'bad receiver' ifTrue:
  		[^self error: 'receiver must be of class Array'].
  	ec == #'bad argument' ifTrue:
  		[^self error: (otherArray class == Array
  						ifTrue: ['arg must be of class Array']
  						ifFalse: ['receiver and argument must have the same size'])].
  	ec == #'inappropriate operation' ifTrue:
  		[^self error: 'can''t become immediates such as SmallIntegers or Characters'].
  	ec == #'object is pinned' ifTrue:
  		[^self error: 'can''t become pinned objects'].
  	ec == #'insufficient object memory' ifTrue:
  		[self error: 'The virtual machine is out-of-date.  Please upgrade.'].
  	self primitiveFailed!