node -c rejects BOM before #!, but node accepts it #27767

Version: v12.1.0

$ node -e 'require("fs").writeFileSync("test.js", `\u{FEFF}#!`, "utf8")'
$ node -c test.js
(function (exports, require, module, __filename, __dirname) { #!
                                                              ^
SyntaxError: Invalid or unexpected token
$ echo $?
1
$ node test.js
$ echo $?
0

The bug is that check_syntax.js call stripShebang before stripBOM, but the actual loader calls stripBOM before stripShebag.

It's not totally clear which behavior is desired. The original bug which lead to the introduction of stripBOM actually had a script with a BOM preceding the #!, though the test included in that commit doesn't. But unix systems generally require the #! to be the first two bytes for it to be parsed as an interpreter directive, which means it cannot be preceded by a BOM.