I cannot believe it but it seems to work. I would really appreaciate if someone can take a look, and consider to integrate it.
Having no way to execute a method on a receveir WITHOUT sending a message to the object, is really a problem. I am implementing proxies, which understand NOTHING (their class has method dictionary in nil and I use the cannotInterpret trick) and so I CANNOT send a message because I will be in loop. I have a similar problem with primitiveChangeClassTo:  but fortunately, Eliot did #adoptInstance: which receiver is the class and not the object.

Anyway, this is the method

CompiledMethod >> executeWithReceiver: aReceiver arguments: anArray
 "Execute the compiledMethod against the aReceiver and args in argArray."

<primitive: 190>
   self primitiveFailed


And this is the primitive.


StackInterpreterPrimitives >> primitiveExecuteWithReceiverArguments
    "method, recevier, and the array of arguments are on top of stack.  Execute method against receiver and args.
     Set primitiveFunctionPointer because no cache lookup has been done for the method, and
     hence primitiveFunctionPointer is stale."
    | receiverMethod argCnt argumentArray primitiveIndex receiverObject |
    receiverMethod := self stackValue: 2.
    receiverObject := self stackValue: 1.
    argumentArray := self stackTop.
    ((objectMemory isOopCompiledMethod: receiverMethod)
     and: [objectMemory isArray: argumentArray]) ifFalse:
        [^self primitiveFailFor: PrimErrBadArgument].
    argCnt := self argumentCountOf: receiverMethod.
    argCnt = (objectMemory fetchWordLengthOf: argumentArray) ifFalse:
        [^self primitiveFailFor: PrimErrBadNumArgs].
    self pop: 3.
    self push: receiverObject.
    0 to: argCnt - 1 do:
        [:i|
        self push: (objectMemory fetchPointer: i ofObject: argumentArray)].
    newMethod := receiverMethod.
    primitiveIndex := self primitiveIndexOf: newMethod.
    primitiveFunctionPointer := self functionPointerFor: primitiveIndex inClass: nil.
    argumentCount := argCnt.
    "We set the messageSelector for executeMethod below since things
     like the at cache read messageSelector and so it cannot be left stale."
    messageSelector := objectMemory nilObject.
    self executeNewMethod.
    "Recursive xeq affects primErrorCode"
    self initPrimCall


Thanks for taking a look and hopefully integrate this or something better,

Mariano