Retire DynamicValueTypeInfoNeedsUpdate() (NFC)

This function was introduced to detect a stale Swift scratch
context. Today it doesn't make much sense, since all ValueObjects
prefer to store their types as TypeSystemSwiftTypeRef types, and
dynamic type resolution is done using type metadata, and not in
SwiftASTContext space. This avoids a very costly initialization of the
Swift compiler triggered by ValueObjectDynamicValue.

rdar://124487859

Author: adrian-prantl

lldb/include/lldb/Core/ValueObjectDynamicValue.h

@@ -106,10 +106,6 @@ class ValueObjectDynamicValue : public ValueObject {
 
   bool HasDynamicValueTypeInfo() override { return true; }
 
-  /// Determine whether the scratch AST context has been replaced
-  /// since this dynamic type has been created.
-  bool DynamicValueTypeInfoNeedsUpdate();
-
   CompilerType GetCompilerTypeImpl() override;
 
   Address m_address; ///< The variable that this value object is based upon

lldb/source/Core/ValueObject.cpp

@@ -129,17 +129,6 @@ bool ValueObject::UpdateValueIfNeeded(bool update_format) {
 
   bool did_change_formats = false;
 
-  // BEGIN SWIFT
-  // Swift: Check whether the dynamic type system became stale.
-  if (m_dynamic_value) {
-    auto *dyn_val = static_cast<ValueObjectDynamicValue *>(m_dynamic_value);
-    if (dyn_val->DynamicValueTypeInfoNeedsUpdate()) {
-      dyn_val->SetNeedsUpdate();
-      SetNeedsUpdate();
-    }
-  }
-  // END SWIFT
-
   if (update_format)
     did_change_formats = UpdateFormatsIfNeeded();
 

lldb/source/Core/ValueObjectDynamicValue.cpp

@@ -440,23 +440,3 @@ void ValueObjectDynamicValue::SetLanguageFlags(uint64_t flags) {
   else
     this->ValueObject::SetLanguageFlags(flags);
 }
-
-bool ValueObjectDynamicValue::DynamicValueTypeInfoNeedsUpdate() {
-  if (GetPreferredDisplayLanguage() != eLanguageTypeSwift)
-    return false;
-
-  if (!m_dynamic_type_info.HasType())
-    return false;
-
-#ifdef LLDB_ENABLE_SWIFT
-  auto cached_ctx = m_value.GetCompilerType().GetTypeSystem();
-  std::optional<SwiftScratchContextReader> scratch_ctx(
-      GetSwiftScratchContext());
-
-  if (!scratch_ctx || !cached_ctx)
-    return true;
-  return (void*)cached_ctx.GetSharedPointer().get() != (void*)scratch_ctx->get();
-#else // !LLDB_ENABLE_SWIFT
-  return false;
-#endif // LLDB_ENABLE_SWIFT
-}