Configuration resolution seems at least square in number of language? overrides

[mueheg]

nb: I can't reopen #168869 but it still reproduces exactly as outlined in my original report.

Does this issue occur when all extensions are disabled?: Yes

• VS Code Version: 1.77.1
• OS Version: vscode.dev

Steps to Reproduce:

Open settings.json
Paste a large number of per language overrides, for instance generated by running this JS snippet:

let overrides='';
for (let i = 0; i<500; ++i) { 
  overrides+= `    "[julia${i}]": { "editor.defaultFormatter": "vscode.typescript-language-features" },`;
}

paste contents of overrides into settings.json

At a very first glance, it looks like the code starting from https://github.com/microsoft/vscode/blob/main/src/vs/platform/configuration/common/configurationModels.ts#L697 is at least square in the number of overrides.

I put a counter in the code and with ~130 overrides I see getContentsForOverrideIdentifer being invoked 150000 times when I load settings / switch between user and workspace within the settings UI.

[sandy081]

Assigning to current milestone for investigation