Delete leftover dead code.

Author: adrian-prantl

lldb/include/lldb/Symbol/Type.h

@@ -220,7 +220,6 @@ class Type : public std::enable_shared_from_this<Type>, public UserID {
   Declaration m_decl;
   CompilerType m_compiler_type;
   ResolveState m_compiler_type_resolve_state;
-  bool m_is_swift_fixed_value_buffer = false;
   /// Language-specific flags.
   Payload m_payload;