Update expectations files.

pkg/front_end/testcases/rasta/switch_fall_through.dart.direct.expect

 library;
 import self as self;
 import "dart:core" as core;
 
 static method main() → dynamic {
   #L1:
   switch(1) {
     #L2:
     case 1:
       {
         {
           "No fall-through error needed.";
           break #L1;
           ;
         }
       }
     #L3:
     case 2:
       {
         {
           "Fall-through error needed.";
           if(true) {
             break #L1;
           }
         }
-        throw core::_fallThroughError();
+        throw new core::FallThroughError::•();
       }
     #L4:
     case 3:
       {
         try {
           "No fall-through error needed.";
         }
         finally {
           break #L1;
         }
       }
     #L5:
     case 4:
       {
         try {
           "No fall-through error needed.";
           break #L1;
         }
         finally {
         }
       }
     #L6:
     case 5:
       {
         try {
           "Fall-through error needed.";
         }
         finally {
         }
-        throw core::_fallThroughError();
+        throw new core::FallThroughError::•();
       }
     #L7:
     case 10000:
       {
         "Should be last. No fall-through error, falling through allowed here.";
       }
   }
 }