src/vs/editor/common/cursor/cursorDeleteOperations.ts/DeleteOperations/getPositionAfterDeleteLeft
class DeleteOperations:	private static getPositionAfterDeleteLeft(position: Position, model: ICursorSimpleModel): Position {
		if (position.column > 1) {
			// Convert 1-based columns to 0-based offsets and back.
			const idx = strings.getLeftDeleteOffset(position.column - 1, model.getLineContent(position.lineNumber));
			return position.with(undefined, idx + 1);
		} else if (position.lineNumber > 1) {
			const newLine = position.lineNumber - 1;
			return new Position(newLine, model.getLineMaxColumn(newLine));
		} else {
			return position;
		}
	}