Fix build with llvm-19
https://phabricator.services.mozilla.com/D209108

Index: src/third_party/mozjs-60/extract/js/src/threading/ExclusiveData.h
--- src/third_party/mozjs-60/extract/js/src/threading/ExclusiveData.h.orig
+++ src/third_party/mozjs-60/extract/js/src/threading/ExclusiveData.h
@@ -120,13 +120,6 @@ class ExclusiveData
         release();
     }
 
-    ExclusiveData(ExclusiveData&& rhs)
-      : lock_(mozilla::Move(rhs.lock))
-    {
-        MOZ_ASSERT(&rhs != this, "self-move disallowed!");
-        new (mozilla::KnownNotNull, value_.addr()) T(mozilla::Move(*rhs.value_.addr()));
-    }
-
     ExclusiveData& operator=(ExclusiveData&& rhs) {
         this->~ExclusiveData();
         new (mozilla::KnownNotNull, this) ExclusiveData(mozilla::Move(rhs));
