src/vs/platform/extensionManagement/node/extensionsScanner.ts/ExtensionsScanner/scanSystemExtensions
class ExtensionsScanner:	private async scanSystemExtensions(): Promise<ILocalExtension[]> {
		this.logService.trace('Started scanning system extensions');
		const systemExtensionsPromise = this.scanDefaultSystemExtensions();
		if (this.environmentService.isBuilt) {
			return systemExtensionsPromise;
		}

		// Scan other system extensions during development
		const devSystemExtensionsPromise = this.scanDevSystemExtensions();
		const [systemExtensions, devSystemExtensions] = await Promise.all([systemExtensionsPromise, devSystemExtensionsPromise]);
		return [...systemExtensions, ...devSystemExtensions];
	}