Detect more => typos

Handle and recover `match expr { pat >= { arm } }`.

compiler/rustc_ast/src/token.rs

@@ -388,7 +388,8 @@ impl TokenKind {
         match *self {
             Comma => Some(vec![Dot, Lt, Semi]),
             Semi => Some(vec![Colon, Comma]),
-            FatArrow => Some(vec![Eq, RArrow]),
+            Colon => Some(vec![Semi]),
+            FatArrow => Some(vec![Eq, RArrow, Ge, Gt]),
             _ => None,
         }
     }