• JS: set vardecl size limit to prevent timeout with OSSFuzz
• Change minify.writer.Writer return type to io.WriteCloser, fixes #524
• JS: support declarations in export default, add syntax errors for variable declarations, fixes https://github.com/tdewolff/minify/issues/525
• JS: fix when parenthesized expr has assignments for the same variable which only when interpreted as arguments for an arrow func should error, fixes https://github.com/tdewolff/minify/issues/528