[ObjC] Don't undefine / redefine symbols and types that already exist in the view

This can cause functions to be reanalyzed unnecessarily when the view is
loaded from a bndb. Fixes
#8051.

Author: bdash

objectivec/objc.cpp

@@ -412,10 +412,16 @@ void ObjCProcessor::DefineObjCSymbol(
 
 	auto defineSymbol = [this](Ref<Symbol> symbol, const Confidence<Ref<Type>>& type) {
 		uint64_t symbolAddress = symbol->GetAddress();
-		// Armv7/Thumb: This will rewrite the symbol's address.
-		// e.g. We pass in 0xc001, it will rewrite it to 0xc000 and create the function w/ the "thumb2" arch.
 		if (Ref<Symbol> existingSymbol = m_data->GetSymbolByAddress(symbolAddress))
+		{
+			if (existingSymbol->IsAutoDefined() && existingSymbol->GetType() == symbol->GetType() && existingSymbol->GetRawNameRef() == symbol->GetRawNameRef())
+				return;
+
 			m_data->UndefineAutoSymbol(existingSymbol);
+		}
+
+		// Armv7/Thumb: This will rewrite the symbol's address.
+		// e.g. We pass in 0xc001, it will rewrite it to 0xc000 and create the function w/ the "thumb2" arch.
 		Ref<Platform> targetPlatform = m_data->GetDefaultPlatform()->GetAssociatedPlatformByAddress(symbolAddress);
 		if (symbol->GetType() == FunctionSymbol)
 		{
@@ -1159,6 +1165,11 @@ void ObjCProcessor::GenerateClassTypes()
 {
 	for (auto& [_, cls] : m_classes)
 	{
+		QualifiedName classTypeName = cls.name;
+		std::string classTypeId = Type::GenerateAutoTypeId("objc", classTypeName);
+		if (m_data->GetTypeById(classTypeId))
+			continue;
+
 		QualifiedName typeName;
 		StructureBuilder classTypeBuilder;
 		bool failedToDecodeType = false;
@@ -1191,8 +1202,6 @@ void ObjCProcessor::GenerateClassTypes()
 		if (failedToDecodeType)
 			continue;
 		auto classTypeStruct = classTypeBuilder.Finalize();
-		QualifiedName classTypeName = cls.name;
-		std::string classTypeId = Type::GenerateAutoTypeId("objc", classTypeName);
 		Ref<Type> classType = Type::StructureType(classTypeStruct);
 		QualifiedName classQualName = m_data->DefineType(classTypeId, classTypeName, classType);
 		cls.associatedName = classTypeName;