remove isModuleSource

spec.emu

@@ -2006,17 +2006,6 @@ contributors: Luca Casonato, Guy Bedford, Nicolò Ribaudo
         <p>The initial value of %AbstractModuleSource%`.prototype` is the %AbstractModuleSource% prototype object.</p>
         <p>This property has the attributes { [[Writable]]: *false*, [[Enumerable]]: *false*, [[Configurable]]: *false* }.</p>
       </emu-clause>
-
-      <emu-clause id="sec-%abstractmodulesource%.isModuleSource">
-        <h1>%AbstractModuleSource%.isModuleSource ( )</h1>
-        <p>This method performs the following steps when called:</p>
-        <emu-alg>
-          1. Let _O_ be the *this* value.
-          1. Let _sourceRecordResult_ be Completion(HostGetModuleSourceRecord(_O_)).
-          1. If _sourceRecordResult_ is a normal completion, return *true*.
-          1. Return *false*.
-        </emu-alg>
-      </emu-clause>
     </emu-clause>
 
     <emu-clause id="sec-properties-of-the-%abstractmodulesource%-prototype-object">