Recession concerns may be weighing on consumer minds, but General Motors Co. showed Tuesday those fears aren’t affecting its sales or financial performance. Powered by a successful first three months of the year, the Detroit automaker outperformed Wall Street expectations in its first-quarter earnings. And it increased guidance for the year, upping its adjusted earnings before taxes target to between $11 billion and $13 billion, an improvement over the previous outlook of $10.5 billion to $12.5 billion. The results are the first glimpse into a crucial year for GM and crosstown rivals Ford Moto...