dropped sequence elements leads to SyntaxError: Function statements require a function name

[kzc]

• Rollup Version: rollup v2.50.2
• Operating System (or Browser): n/a
• Node Version (if applicable): n/a

Repro

$ cat seqfnexpr.js 
1, 2, function(){ console.log("PASS"); }(), 3;

Expected Behavior

$ cat seqfnexpr.js | node
PASS

Actual Behavior

$ cat seqfnexpr.js | rollup --silent | node
[stdin]:1
function(){ console.log("PASS"); }();
^^^^^^^^

SyntaxError: Function statements require a function name