d19d864e79
Improve structured tuple struct suggestion Previously, the span was just for the constructor name, which meant it would result in syntactically-invalid code when applied. Now, the span is for the entire expression. I also changed it to use `span_suggestion_verbose`, for two reasons: 1. Now that the suggestion span has been corrected, the output is a bit cluttered and hard to read. Putting the suggestion its own window creates more space. 2. It's easier to see what's being suggested, since now the version after the suggestion is applied is shown. r? `@davidtwco`
For high-level intro to how type checking works in rustc, see the type checking chapter of the rustc dev guide.