Disallow constants to be null

index.bs

@@ -1603,17 +1603,15 @@ Note: These three names are the names of properties that may exist on
 
 The type of a constant (matching <emu-nt><a href="#prod-ConstType">ConstType</a></emu-nt>)
 must not be any type other than
-a [=primitive type=]
-or a [=nullable type|nullable=] primitive type.
+a [=primitive type=].
 If an [=identifier=] is used,
 it must reference a [=typedef=]
-whose type is a primitive type or a nullable primitive type.
+whose type is a primitive type.
 
 The <emu-nt><a href="#prod-ConstValue">ConstValue</a></emu-nt> part of a
 constant declaration gives the value of the constant, which can be
 one of the two boolean literal tokens (<emu-t>true</emu-t>
-and <emu-t>false</emu-t>),
-the <emu-t>null</emu-t> token, an
+and <emu-t>false</emu-t>), an
 <emu-t class="regex"><a href="#prod-integer">integer</a></emu-t> token,
 a <emu-t class="regex"><a href="#prod-decimal">decimal</a></emu-t> token,
 or one of the three special floating point constant values
@@ -1756,7 +1754,6 @@ The following extended attributes are applicable to constants:
         BooleanLiteral
         FloatLiteral
         integer
-        "null"
 </pre>
 
 <pre class="grammar" id="prod-BooleanLiteral">
@@ -1775,8 +1772,8 @@ The following extended attributes are applicable to constants:
 
 <pre class="grammar" id="prod-ConstType">
     ConstType :
-        PrimitiveType Null
-        identifier Null
+        PrimitiveType
+        identifier
 </pre>
 
 <div class="example">
@@ -2351,6 +2348,7 @@ The following extended attributes are applicable to operations:
         ConstValue
         string
         "[" "]"
+        "null"
 </pre>
 
 <pre class="grammar" id="prod-Operation">