The General Motors Corporation, reeling from the abrupt shift to small cars by consumers, posted a $15.5 billion second-quarter loss on Friday, in results weighed down by restructuring charges and write-downs. According to the earnings statement, the loss included $9.1 billion in one-time charges, $3.3 billion of which was for employee buyouts. [Snip] Excluding one-time charges, G.M. had a loss of $6.3 billion or $11.21 a share, compared with income of $1.3 billion or $2.29 a share in the same period last year. Included in the results, the statement said, was $1.3 billion in write-offs that reflect the drop in...