formals(x)<- drops attributes including class

Just checking in to see whether it is intended or not that assigning
new formals to a function/closure causes any attributes to be dropped:

EXAMPLE:

fcn <- structure(function() {}, foo="foo", class=c("foo"))
str(fcn)

function ()
  - attr(*, "srcref")=Class 'srcref'  atomic [1:8] 1 18 1 30 18 30 1 1
   .. ..- attr(*, "srcfile")=Classes 'srcfilecopy', 'srcfile' <environment: 0x000
000000c00d128>
  - attr(*, "foo")= chr "foo"
  - attr(*, "class")= chr "foo"

formals(fcn) <- list(a=1)
str(fcn)

function (a = 1)

attributes(fcn)

NULL


TROUBLESHOOTING:

From the definition of formals()<-, it's quite clear why this happens:

`formals<-`

function (fun, envir = environment(fun), value)
{
     bd <- body(fun)
     as.function(c(value, if (is.null(bd) || is.list(bd)) list(bd) else bd),
         envir)
}
<bytecode: 0x000000000b97a848>
<environment: namespace:base>


I'm fine with this, but I just wanted to make sure it's not overlooked.

/Henrik