[lldb] Preserve original symbol of Mangled function names

Author: kastiglione

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

@@ -2509,7 +2509,9 @@ Function *DWARFASTParserClang::ParseFunctionFromDWARF(
       // If the mangled name is not present in the DWARF, generate the
       // demangled name using the decl context. We skip if the function is
       // "main" as its name is never mangled.
-      func_name.SetValue(ConstructDemangledNameFromDWARF(die));
+      func_name.SetDemangledName(ConstructDemangledNameFromDWARF(die));
+      // Ensure symbol is preserved (as the mangled name).
+      func_name.SetMangledName(ConstString(name));
     } else
       func_name.SetValue(ConstString(name));