Add --disableLanguageFeature CLI switch and MSBuild property to selectively disable language features#19167

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copilot/add-disable-language-feature-cli

Commits on Dec 17, 2025

Fix null handling and use Set for disabledLanguageFeatures

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Update help baseline with --disableLanguageFeature option

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Add DisabledLanguageFeatures MSBuild property support

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Commits on Dec 18, 2025

Pass DisabledLanguageFeatures property to Fsc task in targets file

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Move release notes to correct file (.Language/preview.md)

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Commits on Dec 19, 2025

Fix nullness warning in TryParseFeature by using box before downcast

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