Opening many editors cripples my machine

Environment

• OS and Version: Windows_NT x64 10.0.19043
• VS Code Version: 1.70.2
• C/C++ Extension Version: 1.11.5

Bug Summary and Steps to Reproduce

Bug Summary:
When opening many editors the extension spins up so many Intellisense processes my PC becomes unresponsive and unusable until I kill them manually or close VSCode. These processes linger even after closing editors.

Steps to reproduce:

1. Open many editors (10-30)
2. Notice the number of Intellisense processes running in the background and the resulting CPU usage
3. Close all editors
4. Notice the Intellisense processes stick around for a long time (possibly until they finish?)

For additional context, this happens in an Unreal Engine codebase (where includes are notoriously heavy and Intellisense has its work cut out for it) while making sweeping refactoring changes. I end up opening 10-20 files at a time, making the same change to each of them, then closing them and starting another batch.

Expected behavior

1. The number of Intellisense processes for unfocused editors is limited to a reasonable number based on the available CPU cores.
2. Intellisense processes are closed immediately when an editor is closed.

Code sample and Logs

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Screenshots

No response

Additional context

No response

Start by reproducing the issue in the reported Windows, VS Code, and C/C++ extension versions with 10–30 editors in an Unreal Engine codebase. Trace how IntelliSense processes are created for unfocused editors and what happens when editors close. Done means unfocused work is reasonably limited by available CPU cores and processes exit promptly after editors are closed.