Bug 1634519 - Removing uses of FunctionBox::function. r=mgaudet

Differential Revision: https://phabricator.services.mozilla.com/D73336

js/src/frontend/Parser.cpp

@@ -7192,6 +7192,10 @@ bool GeneralParser<ParseHandler, Unit>::finishClassConstructor(
   }
 
   if (FunctionBox* ctorbox = classStmt.constructorBox) {
+    // The ctorbox must not have emitted a JSFunction yet since we are still
+    // updating it.
+    MOZ_ASSERT(!ctorbox->hasFunction());
+
     // Amend the toStringEnd offset for the constructor now that we've
     // finished parsing the class.
     ctorbox->extent.toStringEnd = classEndOffset;
@@ -7200,20 +7204,6 @@ bool GeneralParser<ParseHandler, Unit>::finishClassConstructor(
       // Field initialization need access to `this`.
       ctorbox->setHasThisBinding();
     }
-
-    // Set the same information, but on the lazyScript.
-    if (ctorbox->hasFunction()) {
-      if (!ctorbox->emitBytecode) {
-        ctorbox->function()->baseScript()->setToStringEnd(classEndOffset);
-
-        if (numFields > 0) {
-          ctorbox->function()->baseScript()->setFunctionHasThisBinding();
-        }
-      } else {
-        // There should not be any non-lazy script yet.
-        MOZ_ASSERT(ctorbox->function()->isIncomplete());
-      }
-    }
   }
 
   return true;

js/src/frontend/SharedContext.h

@@ -492,12 +492,7 @@ class FunctionBox : public SharedContext {
   bool needsPromiseResult() const { return isAsync() && !isGenerator(); }
 
   bool isArrow() const { return flags_.isArrow(); }
-  bool isLambda() const {
-    if (hasFunction()) {
-      return function()->isLambda();
-    }
-    return functionCreationData().get().flags.isLambda();
-  }
+  bool isLambda() const { return flags_.isLambda(); }
 
   void setDeclaredArguments() {
     immutableFlags_.setFlag(ImmutableFlags::ShouldDeclareArguments);
@@ -572,15 +567,11 @@ class FunctionBox : public SharedContext {
     immutableFlags_.setFlag(ImmutableFlags::AlwaysNeedsArgsObj);
   }
   void setNeedsHomeObject() {
-    MOZ_ASSERT_IF(hasFunction(), function()->allowSuperProperty());
-    MOZ_ASSERT_IF(!hasFunction(),
-                  functionCreationData().get().flags.allowSuperProperty());
+    MOZ_ASSERT(flags_.allowSuperProperty());
     immutableFlags_.setFlag(ImmutableFlags::NeedsHomeObject);
   }
   void setDerivedClassConstructor() {
-    MOZ_ASSERT_IF(hasFunction(), function()->isClassConstructor());
-    MOZ_ASSERT_IF(!hasFunction(),
-                  functionCreationData().get().flags.isClassConstructor());
+    MOZ_ASSERT(flags_.isClassConstructor());
     immutableFlags_.setFlag(ImmutableFlags::IsDerivedClassConstructor);
   }
   void setFunctionHasExtraBodyVarScope() {