[Pharo-project] Remove #class as a Compiler optimization

[Mariano Martinez Peck]

Hi. I have to say that I hate that the compiler associates a special
bytecode for #class and that the VM don't even send the message. I want to
be able to overwrite #class in a proxy for example, or to debug it.

I did some benchmarks disabling such optimization by doing:

    (ParseNode classVarNamed:  'StdSelectors') removeKey: #class ifAbsent:
[].
    Compiler recompileAll.

And the difference is NOTHING in my tests (maybe I am doing something
wrong).

With Standard VM and #class  optimization

[SystemNavigation default allObjectsDo: [:each | each class]] timeToRun
->  aprox 50 miliseconds

With Standard VM and WITHOUT #class  optimization

[SystemNavigation default allObjectsDo: [:each | each class]] timeToRun
->  aprox 60 miliseconds

So...only 10 miliseconds more for asking the class to all the objects in the
system.....(done in a PharoCore 1.3)

With Cog VM and #class  optimization

[SystemNavigation default allObjectsDo: [:each | each class]] timeToRun
->  aprox 13 miliseconds

With Cog VM and WITHOUT #class  optimization

[SystemNavigation default allObjectsDo: [:each | each class]] timeToRun
->  aprox 17 miliseconds

So...only 5 miliseconds more for asking the class to all the objects in the
system.....(done in a PharoCore 1.3)

Considering (5 / 324535) asFloat  0,000015406... of overhead

What do you think?

Mariano