[lldb][DWARF] Do not complete type from declaration die. (#91799)

Fix the problem:
#90663 (comment)
by enhancing a double-check for #90663

Author: ZequanWu

lldb/source/Plugins/SymbolFile/DWARF/DWARFASTParserClang.cpp

@@ -2345,6 +2345,11 @@ bool DWARFASTParserClang::CompleteTypeFromDWARF(const DWARFDIE &die,
 
   if (!die)
     return false;
+  ParsedDWARFTypeAttributes attrs(die);
+  bool is_forward_declaration = IsForwardDeclaration(
+      die, attrs, SymbolFileDWARF::GetLanguage(*die.GetCU()));
+  if (is_forward_declaration)
+    return false;
 
   const dw_tag_t tag = die.Tag();