Change Syntax Error to emu-note

Author: jridgewell

spec.html

@@ -148,13 +148,14 @@ <h1>Updated Syntactic Grammar Productions</h1>
         `?.` IdentifierName
         `?.` Arguments[?Yield, ?Await]
         `?.` TemplateLiteral[?Yield, ?Await, +Tagged]
-        <ins>`?.` PrivateIdentifier</ins>
         OptionalChain[?Yield, ?Await]  `[` Expression[+In, ?Yield, ?Await] `]`
         OptionalChain[?Yield, ?Await] `.` IdentifierName
         OptionalChain[?Yield, ?Await] Arguments[?Yield, ?Await]
         OptionalChain[?Yield, ?Await] TemplateLiteral[?Yield, ?Await, +Tagged]
         <ins>OptionalChain[?Yield, ?Await] `.` PrivateIdentifier</ins>
     </emu-grammar>
+
+    <emu-note>`?.` PrivateIdentifier is currently a unstated Syntax Error</emu-note>
   </emu-clause>
 
   <emu-clause id="sec-static-semantics-early-errors">
@@ -219,12 +220,6 @@ <h1>Static Semantics: Early Errors</h1>
       <li>It is a Syntax Error if AllPrivateIdentifiersValid of |ModuleItemList| with an empty List as an argument is *false*.</li>
     </ul>
     <emu-note type=editor>References to |PrivateIdentifier|s which are not lexically present cause an early error.</emu-note>
-
-    <emu-grammar>OptionalChain : `?.` PrivateIdentifier</emu-grammar>
-    <ul>
-      <li>It is a Syntax Error if any code matches this production.</li>
-    </ul>
-    <emu-note>This production exists to explicitly reserve the syntax for future proposals.</emu-note>
   </emu-clause>
 
   <emu-clause id="sec-all-private-identifiers-valid" aoid="AllPrivateIdentifiersValid" oldids="sec-all-private-names-valid">