Upgrade to rustfmt 0.8.0.

Lots of changes this time.

Worked around what looks like a rustfmt bug in parse_inst_operands where
a large match was nested inside Ok().

lib/cretonne/src/ir/jumptable.rs

@@ -66,7 +66,10 @@ impl JumpTableData {
     ///
     /// This returns an iterator that skips any empty slots in the table.
     pub fn entries<'a>(&'a self) -> Entries {
-        Entries(self.table.iter().cloned().enumerate())
+        Entries(self.table
+                    .iter()
+                    .cloned()
+                    .enumerate())
     }
 
     /// Access the whole table as a mutable slice.
@@ -101,7 +104,10 @@ impl Display for JumpTableData {
             Some(first) => write!(fmt, "jump_table {}", first)?,
         }
 
-        for dest in self.table.iter().skip(1).map(|e| e.expand()) {
+        for dest in self.table
+                .iter()
+                .skip(1)
+                .map(|e| e.expand()) {
             match dest {
                 None => write!(fmt, ", 0")?,
                 Some(ebb) => write!(fmt, ", {}", ebb)?,