Check value-follows-name case in symbol Save As.

Fixes https://gitlab.com/kicad/code/kicad/-/issues/15647

eeschema/symbol_editor/symbol_editor.cpp

@@ -663,6 +663,7 @@ void SYMBOL_EDIT_FRAME::saveSymbolAs()
     LIB_ID   old_lib_id = symbol->GetLibId();
     wxString symbolName = old_lib_id.GetLibItemName();
     wxString libraryName = old_lib_id.GetLibNickname();
+    bool     valueFollowsName = symbol->GetValueField().GetText() == symbolName;
     wxString msg;
     bool     done = false;
 
@@ -730,6 +731,9 @@ void SYMBOL_EDIT_FRAME::saveSymbolAs()
     LIB_SYMBOL new_symbol( *symbol );
     new_symbol.SetName( symbolName );
 
+    if( valueFollowsName )
+        new_symbol.GetValueField().SetText( symbolName );
+
     m_libMgr->UpdateSymbol( &new_symbol, libraryName );
     SyncLibraries( false );
     m_treePane->GetLibTree()->SelectLibId( LIB_ID( libraryName, new_symbol.GetName() ) );