Bug 1899090 - Part 2: Rebuild the incremental encoding with InitialStencilAndDelazifications. r=nbp

Create InitialStencilAndDelazifications and associate it to ScriptSourceObject,
and store on-demand delazifications into the InitialStencilAndDelazifications.

InitialStencilAndDelazifications is merged into single CompilationStencil when
finishing, but the JS::Stencil-based API is going to be rewritten later not
to merge.

Differential Revision: https://phabricator.services.mozilla.com/D230378

dom/script/ScriptLoader.cpp

@@ -2762,7 +2762,7 @@ static void InstantiateStencil(
   }
 
   if (aEncodeBytecode) {
-    if (!JS::StartIncrementalEncoding(aCx, std::move(aStencil),
+    if (!JS::StartIncrementalEncoding(aCx, script, aStencil,
                                       incrementalEncodingAlreadyStarted)) {
       aRv.NoteJSContextException(aCx);
       return;