at-exp, scribble: remove distinctness of @{}-introduced newlines

original commit: fe3b6ea0032a6cdee6aa8720b349ef1032fed803

collects/scribblings/scribble/reader.scrbl

@@ -629,29 +629,6 @@ newlines are read as a @racket["\n"] string
        baz }
 }===|
 
-In the parsed S-expression syntax, a single newline string is used for
-all newlines; you can use @racket[eq?] to identify this line.  This
-can be used to identify newlines in the original @nonterm{text-body}.
-
-@; FIXME: unfortunate code duplication (again):
-@interaction[
-(eval:alts
-  (let ([nl (car @#,tt["@'{"]
-                 @#,tt["  }"])])
-    (for-each (lambda (x) (display (if (eq? x nl) "\n... " x)))
-              @#,tt["@`{foo"]
-              @#,elem[@tt["   @"] @racket[,@(list "bar" "\n" "baz")]]
-              @#,tt["   blah}}"])
-    (newline))
-  (let ([nl (car @'{
-                   })])
-    (for-each (lambda (x) (display (if (eq? x nl) "\n... " x)))
-              @`{foo
-                 @,@(list "bar" "\n" "baz")
-                 blah})
-    (newline)))
-]
-
 Spaces at the beginning of body lines do not appear in the resulting
 S-expressions, but the column of each line is noticed, and all-space
 indentation strings are added so the result has the same indentation.

collects/tests/scribble/reader.rkt

@@ -744,18 +744,6 @@ foo
 -@eval->
 "/Note/: *This is _not_ a pipe*."
 ---
-(let ([nl (car @'{
-                 })]
-      [o (open-output-string)])
-  (for-each (lambda (x) (display (if (eq? x nl) "\n... " x) o))
-            @`{foo
-               @,@(list "bar" "\n" "baz")
-               blah})
-  (newline o)
-  (get-output-string o))
--@eval->
-"foo\n... bar\nbaz\n... blah\n"
----
 (require (for-syntax scheme/base))
 (let-syntax ([foo
               (lambda (stx)