Parameters cannot be immutable

[jpellegrini]

Hi @egallesio !

I believe this is not supposed to happen...

stklos> (symbol-mutable? 'keyword-colon-position )
#t
stklos> (symbol-immutable! 'keyword-colon-position )
stklos> (keyword-colon-position )
both
stklos> (keyword-colon-position 'none)
stklos> (keyword-colon-position )
none

Changing a parameter doesn't seem to be equivalent to re-define it... It is more like re-set!ing it.
So STklos should either make the parameter actually immutable or not allow symbol-immutable! to operate on parameters. Do you agree?