Bug 1781183 - Part 4: Simplify BytecodeEmitter constructor. r=bthrall

`parent` parameter is used only internally.
Remove `parent` parameter from public methods.

This simplifies the stack limit parameter in the next patch.

Depends on D152774

Differential Revision: https://phabricator.services.mozilla.com/D152775

js/src/frontend/BytecodeCompiler.cpp

@@ -627,8 +627,7 @@ static bool EmplaceEmitter(CompilationState& compilationState,
                            const EitherParser& parser, SharedContext* sc) {
   BytecodeEmitter::EmitterMode emitterMode =
       sc->selfHosted() ? BytecodeEmitter::SelfHosting : BytecodeEmitter::Normal;
-  emitter.emplace(/* parent = */ nullptr, parser, sc, compilationState,
-                  emitterMode);
+  emitter.emplace(parser, sc, compilationState, emitterMode);
   return emitter->init();
 }
 
@@ -1132,8 +1131,8 @@ static bool CompileLazyFunctionToStencilMaybeInstantiate(
     return false;
   }
 
-  BytecodeEmitter bce(/* parent = */ nullptr, &parser, pn->funbox(),
-                      compilationState, BytecodeEmitter::LazyFunction);
+  BytecodeEmitter bce(&parser, pn->funbox(), compilationState,
+                      BytecodeEmitter::LazyFunction);
   if (!bce.init(pn->pn_pos)) {
     return false;
   }

js/src/frontend/BytecodeEmitter.cpp

@@ -153,11 +153,10 @@ BytecodeEmitter::BytecodeEmitter(BytecodeEmitter* parent,
   parser = handle;
 }
 
-BytecodeEmitter::BytecodeEmitter(BytecodeEmitter* parent,
-                                 const EitherParser& parser, SharedContext* sc,
+BytecodeEmitter::BytecodeEmitter(const EitherParser& parser, SharedContext* sc,
                                  CompilationState& compilationState,
                                  EmitterMode emitterMode)
-    : BytecodeEmitter(parent, sc, compilationState, emitterMode) {
+    : BytecodeEmitter(nullptr, sc, compilationState, emitterMode) {
   ep_.emplace(parser);
   this->parser = ep_.ptr();
 }

js/src/frontend/BytecodeEmitter.h

@@ -314,6 +314,10 @@ struct MOZ_STACK_CLASS BytecodeEmitter {
   BytecodeEmitter(BytecodeEmitter* parent, SharedContext* sc,
                   CompilationState& compilationState, EmitterMode emitterMode);
 
+  BytecodeEmitter(BytecodeEmitter* parent, BCEParserHandle* handle,
+                  SharedContext* sc, CompilationState& compilationState,
+                  EmitterMode emitterMode);
+
   void initFromBodyPosition(TokenPos bodyPosition);
 
   /*
@@ -325,20 +329,15 @@ struct MOZ_STACK_CLASS BytecodeEmitter {
   void reportNeedMoreArgsError(CallNode* callNode, uint32_t requiredArgs);
 
  public:
-  BytecodeEmitter(BytecodeEmitter* parent, BCEParserHandle* handle,
-                  SharedContext* sc, CompilationState& compilationState,
-                  EmitterMode emitterMode = Normal);
-
-  BytecodeEmitter(BytecodeEmitter* parent, const EitherParser& parser,
-                  SharedContext* sc, CompilationState& compilationState,
+  BytecodeEmitter(const EitherParser& parser, SharedContext* sc,
+                  CompilationState& compilationState,
                   EmitterMode emitterMode = Normal);
 
   template <typename Unit>
-  BytecodeEmitter(BytecodeEmitter* parent,
-                  Parser<FullParseHandler, Unit>* parser, SharedContext* sc,
+  BytecodeEmitter(Parser<FullParseHandler, Unit>* parser, SharedContext* sc,
                   CompilationState& compilationState,
                   EmitterMode emitterMode = Normal)
-      : BytecodeEmitter(parent, EitherParser(parser), sc, compilationState,
+      : BytecodeEmitter(EitherParser(parser), sc, compilationState,
                         emitterMode) {}
 
   [[nodiscard]] bool init();