src/vs/workbench/contrib/search/common/queryBuilder.ts/QueryBuilder/isMultiline
class QueryBuilder:	private isMultiline(contentPattern: IPatternInfo): boolean {
		if (contentPattern.isMultiline) {
			return true;
		}

		if (contentPattern.isRegExp && isMultilineRegexSource(contentPattern.pattern)) {
			return true;
		}

		if (contentPattern.pattern.indexOf('\n') >= 0) {
			return true;
		}

		return !!contentPattern.isMultiline;
	}