I've noticed that doits appear to be taking a long time to run (I
recently had a process that seemed to take much longer than it
should...it involved a number of calls to Compiler>>evaluate:).  After
investigating, I realized that every DoIt invokes a #become: operation
to atomically swap out the method dictionary with a copy that has the
#DoIt method removed.  Ah...

So, the question:  Is this really necessary?  Can't we just store the
new method dictionary in the methodDict slot of the class?

Can we safely change the following method:

Behavior>>removeSelectorSimply: selector 
	"Assuming that the argument, selector (a Symbol), is a message
selector 
	in my method dictionary, remove it and its method."

	| oldMethod |
	oldMethod _ self methodDict at: selector ifAbsent: [^ self].
	self methodDict removeKey: selector.

	"Now flush Squeak's method cache, either by selector or by
method"
	oldMethod flushCache.
	selector flushCache.

To be:

Behavior>>removeSelectorSimply: selector 
	"Assuming that the argument, selector (a Symbol), is a message
selector 
	in my method dictionary, remove it and its method."

	| oldMethod newDict |
	oldMethod _ self methodDict at: selector ifAbsent: [^ self].
	newDict _ self methodDict removeKeyNoBecome: selector.
	methodDict _ newDict.

	"Now flush Squeak's method cache, either by selector or by
method"
	oldMethod flushCache.
	selector flushCache.

This should also make fileIns a bit faster, as well as removing methods
in general.

- Stephen