Const strings and bytes were not properly converted to compile time bools.

Contracts @require/@ensure are no longer treated as conditionals, but must be explicitly bool.

lib/std/encoding/csv.c3

@@ -61,7 +61,7 @@ fn CsvRow! CsvReader.read_temp_row(self)
 }
 
 <*
- @require self.allocator `Row already freed`
+ @require self.allocator != null  `Row already freed`
 *>
 fn void CsvRow.free(&self)
 {