src/vs/workbench/common/configuration.ts/ConfigurationMigrationWorkbenchContribution/migrateConfigurations
class ConfigurationMigrationWorkbenchContribution:	private async migrateConfigurations(migrations: ConfigurationMigration[]): Promise<void> {
		await this.migrateConfigurationsForFolder(undefined, migrations);
		for (const folder of this.workspaceService.getWorkspace().folders) {
			await this.migrateConfigurationsForFolder(folder, migrations);
		}
	}