Stage 2.7 Review CZW

[legendecas]

I will post review comments on the issue.

Editorial: Early Error simplification

proposal-deferred-reexports/spec.emu

Lines 1741 to 1746 in 88b6c3a

	<emu-grammar><ins>ExportDeclaration : `export` `defer` ExportFromClause FromClause WithClause? `;`</ins></emu-grammar>
	<ul>
	<li>
	<ins>It is a Syntax Error if |ExportFromClause| is `*`.</ins>
	</li>
	</ul>

This early error could be simplified by specifying with grammar production that:

        ExportDeclaration :
          `export` `defer` ExportFromNamedExports FromClause WithClause? `;`

        ExportFromClause :
          `*`
          ExportFromNamedExports

        ExportFromNamedExports :
          `*` `as` ModuleExportName
          NamedExports