Actually, make it a validation error

Author: lukewagner

design/mvp/WIT.md

@@ -905,6 +905,8 @@ unstable-gate ::= '@unstable' '(' feature-field ')'
 feature-field ::= 'feature' '=' id
 since-gate ::= '@since' '(' 'version' '=' '"' <valid semver> '"' ( ',' feature-field )? ')'
 ```
+As part of WIT validation, any item that refers to another gated item must also
+be gated.
 
 ## Package declaration
 
@@ -1710,11 +1712,6 @@ interface i {
 
   @since(version = "1.1.0")
   g: func();
-
-  @since(version = "1.1.0")
-  type t1 = u32;
-
-  type t2 = t1
 }
 ```
 is encoded as the following component when the target version is `1.0.0`:
@@ -1727,7 +1724,6 @@ is encoded as the following component when the target version is `1.0.0`:
   ))
 )
 ```
-Note that `t2` is transitively disabled since it relied on the gated `t1`.
 If the target version was instead `1.1.0`, the same WIT document would be
 encoded as:
 ```wat
@@ -1736,8 +1732,6 @@ encoded as:
     (export "ns:p/[email protected]" (instance
       (export "f" (func))
       (export "g" (func))
-      (export $t1 "t1" (type (eq u32)))
-      (export "t2" (type (eq $t1)))
     ))
   ))
 )