Change #whileTrue: and #whileFalse: to be primitives

Signed-off-by: Stefan Marr <git@stefan-marr.de>
Merge remote-tracking branch 'SOM-st/master' into loop-primitives
Replace #to:do: with primitive

TruffleSOM also intrinsifies this one.

Signed-off-by: Stefan Marr <git@stefan-marr.de>