src/vs/editor/common/model/textModelSearch.ts/TextModelSearch/_getMultilineMatchRange
class TextModelSearch:	private static _getMultilineMatchRange(model: TextModel, deltaOffset: number, text: string, lfCounter: LineFeedCounter | null, matchIndex: number, match0: string): Range {
		let startOffset: number;
		let lineFeedCountBeforeMatch = 0;
		if (lfCounter) {
			lineFeedCountBeforeMatch = lfCounter.findLineFeedCountBeforeOffset(matchIndex);
			startOffset = deltaOffset + matchIndex + lineFeedCountBeforeMatch /* add as many \r as there were \n */;
		} else {
			startOffset = deltaOffset + matchIndex;
		}

		let endOffset: number;
		if (lfCounter) {
			const lineFeedCountBeforeEndOfMatch = lfCounter.findLineFeedCountBeforeOffset(matchIndex + match0.length);
			const lineFeedCountInMatch = lineFeedCountBeforeEndOfMatch - lineFeedCountBeforeMatch;
			endOffset = startOffset + match0.length + lineFeedCountInMatch /* add as many \r as there were \n */;
		} else {
			endOffset = startOffset + match0.length;
		}

		const startPosition = model.getPositionAt(startOffset);
		const endPosition = model.getPositionAt(endOffset);
		return new Range(startPosition.lineNumber, startPosition.column, endPosition.lineNumber, endPosition.column);
	}