cue fmt --simplify removes ellipsis comments

[NoamTD]

What version of CUE are you using (cue version)?

$ cue version
cue version v0.0.0-20240604142238-b6278c4683a2

go version go1.22.3
      -buildmode exe
       -compiler gc
  DefaultGODEBUG httplaxcontentlength=1,httpmuxgo121=1,tls10server=1,tlsrsakex=1,tlsunsafeekm=1
     CGO_ENABLED 1
          GOARCH arm64
            GOOS darwin
             vcs git
    vcs.revision b6278c4683a28a8d7020695441b439ab80e8b06a
        vcs.time 2024-06-04T14:22:38Z
    vcs.modified true
cue.lang.version v0.9.0

Does this issue reproduce with the latest stable release?

yes

What did you do?

I ran the below test:

# store original cue file as backup
cp test.cue test.cue.golden

exec cue fmt --simplify test.cue
cmp test.cue test.cue.golden

-- test.cue --
// a comment
...
// another comment

What did you expect to see?

a passing test

What did you see instead?

a failing test:

# store original cue file as backup (0.060s)
> cp test.cue test.cue.golden
> exec cue fmt --simplify test.cue
> cmp test.cue test.cue.golden
diff test.cue test.cue.golden
--- test.cue
+++ test.cue.golden
@@ -1,1 +1,3 @@
+// a comment
 ...
+// another comment

FAIL: /var/folders/xj/q6k0bchn5414yzgryc_m1hgw0000gn/T/testscript4089464374/repr.txtar/script.txtar:5: test.cue and test.cue.golden differ
error running repr.txtar in /var/folders/xj/q6k0bchn5414yzgryc_m1hgw0000gn/T/testscript4089464374/repr.txtar